Preventing Injuries in Lower Extremities with Strength ...° fullbúin eftir... · Preventing Injuries in Lower Extremities with Strength Training and Muscular Control Specially Designed

Preventing Injuries in Lower Extremities

with Strength Training and Muscular

Control

Specially Designed Strength Training Program that Reduces Risk of

Injuries in Male Football and Increases Strength and Power

By

Jóhannes Már Marteinsson

Thesis

Master of Science in Exercise Science and Coaching

January 2013

Preventing Injuries in Lower Extremities with

Strength Training and Muscular Control




Thesis submitted to the School of Science and Engineering at Reykjavík

University in partial fulfillment of the requirements for the degree of


January 2014

Supervisor:

Einar Einarsson

Adjunct, Reykjavík University, Iceland

Examiner:

Árni Árnason Phd

i

Preventing Injuries in Lower

Extremities with Strength Training and

Muscular Control




January 2014

Abstract

Aim: Combining different types of strength exercises have been recommended in

strength training for football, it has been a trend for athletes and coaches to have low

emphasis on preventing exercises to injuries. The aim of this study was to mix up

different exercises to make specialized strength program for football, which has

different training factor involved. For instance, explosive power exercise with

dynamic balance, strength exercises with dynamic balance, plyometric high and low

intensity and agilities with dynamic stabilization.

Methods: The participants are selected from two football teams in the Icelandic first

division, within the city limits of Reykjavik. There were 23 males in the research

group and 23 males in the control group. The research is split into a few components.

The hypotheses are tested by analyses of risk factors in lower extremities with 2D

kinematic analyses of forward hop-lunge, also a measurement in strength, power and

speed. Two tests before and after an intervention program (test before the intervention

period = M1 and test after the intervention period = M2). The follow- up was done

with measurements of two test (mid-season and after the season, M3 and M4). The

test that was conducted in the follow-up were 30m speed test, max vertical jump test

and max strength test. Research group did get specialized

ii

strength program through the football season 2013. Were the last measurement was

done. Prior injuries and the frequency of injuries was recorded for both teams before

the study, the injuries were also recorded during the research period, but that was

done after the season ended.

Results: Injuries: There was no significant difference in injuries. Performance in

sprint speed, strength and power: There was significant difference in strength and

sprint speed between test M1 and M2 in the favored to the research group. In max

speed test (F = 5.62, P = 0.02), the research group performed better in 30 meter sprint

compare to control group. In 3x max strength test (F = 4.58, P = 0.04), the research

group performed better in the second test (M2) compared to control group. In the

follow-up, there was no significant difference between the groups.

Kinematics: It seems like the kinematic is inconclusive. There was no significant

difference between the groups related to the difference between the measurements

M1 and M2.

Conclusion: It seems the specialized strength training program was beneficial to the

research group, related to the speed and strength compared to the strength program

for the control group. For the future researches it is needed to find different

kinematic measurement to try to explain the difference frequency of injuries in men

related to different types of strength training programs. For the reason of being able

to predict injuries better and to see what risk factors are changing related to

kinematics, when different types of strength training programs are executed for

football players. There is also a need to have more participants involved in the

studies to get better statistical power.

iii

Fyrirbygging meiðsla í neðri útlimum

með styrktarþjálfun og vöðvastjórnun


Janúar 2013

Úrdráttur

Markmið: Það hefur verið mælt með því að styrktarþjálfun fyrir fótbolta byggist á

því að sameina mismunandi tegundir af þjálfun. Það hefur einnig verið tilhneiging hjá

íþróttamönnum og þjálfurum að sleppa svokallaðri fyrirbygjandi meiðslaþjálfun.

Markmið þessarar rannsóknar var að búa til sérstakt styrktarprógram fyrir fótbolta,

sem hefði marga mismunandi þjálfunarþætti setta inn í hverja styrktaræfingu. Til

dæmis sprengikraftsæfingar með dýnamískum þáttum inn í, styrktaræfingar með

dýnamískum þáttum, plýometrískar æfingar sem eru bæði með mikilli og lítilli ákefð

og fimisæfinar sem hafa dýnamíska stöðuleikaþætti.

Framkvæmd: Þátttakendur voru valdir úr tveimur fótboltaliðum innan borgarmarka

Reykjavíkur. Það voru 23 karlar í rannsóknarhóp og 23 karlar í viðmiðunarhóp.

Þessari rannsókn var skipt upp í nokkra þætti. Skoðaðir voru áhættuþættir í neðri

útlimum með 2D hreyfigreiningu, út frá framstigs hoppprófi með lendingu á öðrum

fæti. Einnig voru skoðaðar frammistöðumælingar á 30 m sprettprófi, hámarks

hoppprófi og hámark styrkprófi. Prófin voru framkvæmd fyrir og eftir inngrip sem

var gert með sérstöku styrktarprógrami (próf fyrir inngrip M1 og próf eftir inngrip

M2). Mælingar á prófum í eftirfylgni voru einnig tvær (prófin voru tekin á miðju

fótboltatímabili M3 og í lok tímabils M4). Prófin sem voru gerð í eftirfylgninni voru

hraðamæling, hámarkshopp og hámarksstyrkur. Rannsóknarhópurinn fékk einnig

áframhaldandi prógram í gegnum alla eftirfylgnina. Fyrri meiðsli voru einnig skráð

hjá þátttakendum áður en rannsókn hófst og einnig voru meiðsli yfir allt

fótboltatímabilið skráð niður, en það var gert eftir tímabilið.

Niðurstöður: Meiðsli: Það var ekki marktækur munur á meiðslum milli hópa.

Framistöðumælingar í hraðaprófi og styrkprófi: Það var marktækur munur á milli

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hópa í mælingum M1 og M2 þar sem rannsóknarhópur náði betri árangri miðað við

viðmiðunarhópinn. Í hraðaprófi (F = 5.62, P = 0.02) og í styrkprófi (F = 4.58, P =

0.04). Aftur á móti var enginn marktækur munur á hópum í hámarks hoppprófi í

mælingum M1 og M2. Einnig var enginn munu á milli hópa í eftirfylgni mælingum

M3 og M4. Hreyfigreining: Það var engin munur á milli hópa í hreyfigreiningunni í

mælingum M1 og M2.

Ályktun: Það lítur út fyrir að sérstakt styrktarprógram geti haft jákvæð áhrif á

bætingu á hraða og styrk miðað við styrktarprógram sem er gert með ketilbjöllum og

þjálfun í lyftingarsal. Fyrir framtíðar rannsóknir væri gott að finna aðrar mælingar

fyrir hreyfigreiningu sem gætu hugsanlega útskýrt betur breytingu á hreyfigum miðað

við fækkun á meiðslum út frá mismunandi tegundum af styrktarþjálfun. Út frá því

væri hugsanlega möguleiki að spá betur fyrir um líkur á meiðslum hjá

fótboltamönnum heldur en er hægt að gera í dag. Það þurfa einnig að vera fleiri

þátttakendur í framtíðarrannsóknum til að fá aukið tölfræðilegt afl.

v

Preventing Injuries in Lower

Extremities with Strength Training and

Muscular Control


Thesis submitted to the School of Science and Engineering at Reykjavík

University in partial fulfillment of the requirements for the degree of


Student:

___________________________________________


Supervisor:

___________________________________________

Einar Einarsson

Examiner:

___________________________________________

Árni Árnason

vi

Acknowledgements

I would like to thank my supervisor Einar Einarsson for his help and guidance

throughout the work of this study and his comments and text review. Ásmundur

Eiríksson, managing director of Kine ehf, for all the help with the technical side of

the study. Also I would like to thank Einar Einarsson for his help and guidance while

performing the tests on the players. I would also like to thank Thelma Dögg

Ragnarsdóttir for help with configuration of SPSS and Excel document. I would also

like to thank Hafrún Kristjansdóttir for statistical guidance. I would like to thank the

coaches of the football teams and the players to for participation in the study, without

them the study would not be possible. Special thanks go to Róbert Magnússon for

review of the Thesis, Pétur Einar Jónsson and Róbert Magnússon, owners of Atlas

endurhæfing ehf for use of the facilities for learning. And last but not least I would

like to thank my wife, my three wonderful kids, friends and family for all the support,

patience and encouragement while working on the thesis.

vii

Contents

1. Introduction ....................................................................................................................... 1

1.1 Injuries in sports .............................................................................................................. 1

1.2 Risk factors for ACL and prevention methods ............................................................... 2

1.3. Hamstrings injuries, risk factor and strengthening ........................................................ 3

1.4. Injuries prevention and strength training ....................................................................... 4

1.5. Strength training ............................................................................................................. 4

1.6. Plyometrics and strength training. ................................................................................. 5

1.7. Purpose of the study, ...................................................................................................... 5

1.8. Research Question and Hypothesis ................................................................................ 6

2. Literature review ................................................................................................................... 7

2.1. Movement of The Human Body, lower extremities and Postural Control ..................... 8

2.3. Neuromuscular adaption and Muscle Strengthening ..................................................... 9

2.4. Injuries in football ........................................................................................................ 10

2.4.1. Frequency of injuries in football ........................................................................... 10

2.4.1.1 Epidemiology of Anterior Cruciate Ligament (ACL) Injuries ............................ 11

2.4.1.2. Osteoarthritis after ACL and meniscus Injuries ................................................. 12

2.4.2. Risk Factors for injuries in lower extremities ....................................................... 12

2.4.2.1 Risk Factor for ACL Injuries .............................................................................. 14

2.4.2.2 Risk factors for Hamstring strain. ....................................................................... 15

2.4.2.2.1 The length and laxity of hamstring .................................................................. 16

2.4.2.2.2. Insufficient strength and muscle imbalance in hamstring as a risk factor ....... 16

2.4.2.2.3. Other risk factors for hamstring injuries. ........................................................ 17

2.5. Risk Factors and Prevention Methods ......................................................................... 18

2.6. Different Strength Training for football and other sports ............................................ 19

2.6.1. Strength Training .................................................................................................. 20

2.6.2. Strength Training, Plyometric and Balance Training. .......................................... 20

2.6.3. Low Intensity Plyometrics. ................................................................................... 21

3. Methods .............................................................................................................................. 22

3.1. The Participants ........................................................................................................... 22

3.2. Measurement Instruments ............................................................................................ 22

3.3. Procedure ..................................................................................................................... 23

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3.3.1. The intervention training program ............................................................................ 27

3.3.2. Injuries registration. .................................................................................................. 29

3.4. Data Process ..................................................................................................................... 29

3.4.1 Analysing of anthropometric data and performance parameters ........................... 30

3.4.2 The history of Injuries. ........................................................................................... 31

3.5. Data Analysis ............................................................................................................... 31

4. Results ................................................................................................................................. 32

4.1. Participation in measurements and the configuration of the participants .................... 32

4.2. Injury profile during the football season ...................................................................... 35

4.3. Difference in performance parameters before and after the intervention period. ........ 36

4.4. The result for the kinematic tests for the research group and the control group before

and after the intervention period. ........................................................................................ 36

4.5. The follow-up between the research group and the control group ............................... 38

4.6. The chances in performance between measurements in tests M1 through M4 with in

the groups. ........................................................................................................................... 39

5. Discussion ........................................................................................................................... 40

5.1. Comparison for injuries: .............................................................................................. 40

5.2. Comparison related to kinematics ................................................................................ 42

5.3. Comparison in Measurements of the Performance tests: ............................................. 45

5.4. Comparison in follow-up measurements: .................................................................... 46

5.5. Disadvantages and Defects .......................................................................................... 47

5.6. Benefits ........................................................................................................................ 47

6. Conclusion .......................................................................................................................... 47

References ............................................................................................................................... 49

7.1. Appendix. Upplýst samþykki ........................................................................................... 65

7.2. Appendix. Kynningarbréf til væntanlegra þátttakenda ................................................... 67

7.3. Appendix. Samstarfsyfirlýsing ......................................................................................... 70

7.4. Appendix. Annual plan and pictures of exercises ............................................................ 71

7.5. Appendix. Strength training program for the control group ........................................... 80

7.6. Appendix. The Intervention Program .............................................................................. 82

7.7 Appendix. Spurningarlisti áður en mælingar eru framkvæmdar .................................... 110

7.8. Appendix. Meiðslaskýrsla eftir tímabil ........................................................................... 119

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Table of figures

Figure 1. Multifactorial model of athletic injuries etiology .................................................... 12

Figure 2. Dynamic recursive model of sport injuries (Meeuwisse et al., 2007). Intrinsic and

extrinsic risk factors. ............................................................................................................... 14

Figure 3 Sync box .................................................................................................................... 22

Figure 4 Time table for the research ....................................................................................... 24

Figure 5. Dropouts during the study for the research group. ................................................ 25

Figure 6. Dropouts during the study for the control group ................................................... 25

Figure 7 the forward jump test (hop lunge) ............................................................................ 27

Figure 8 marker placement ..................................................................................................... 27

Figure 9 Analyzing angles of hip, knee and ankle .................................................................. 31

Table of tables

Table 1. Test sequence in the study ........................................................................................ 24

Table 2 Desciption of every test taken in the study ................................................................ 26

Table 3. Mean differences between the groups ...................................................................... 33

Table 4 Frequency of previous injuries and the players that did not get injured..................... 33

Table 5. The difference in frequency of previus injuries and the players that did not get

injuried .................................................................................................................................... 34

Table 6 Profile of previous injuries and days absent from competition and practice. ........... 34

Table 7 Profile of injuries during the season and days absent from competition and practice

................................................................................................................................................ 35

Table 8. Frequency of injuries during season and the number of players that did not get

injured ..................................................................................................................................... 36

Table 9. Mean difference in performance parameters before and after the intervention

program ................................................................................................................................... 36

Table 10. The difference of the mean for the groups in valgus motion in the knee before and

after the intervention periode .................................................................................................. 37

Table 11. The difference of the mean in the research and control groups for the flexion in the

hip before and after the intervention periode .......................................................................... 37

Table 12. The difference of the mean for the groups in flexion in the knee before and after the

intervention period .................................................................................................................. 38

Table 13. The difference of the mean for groups in flexion in the ankle before and after the

intervention period .................................................................................................................. 38

Table 14. Mean difference in performance parameters in the follow-up. ............................... 39

Table 15. The mean difference in performance parameters within groups in the follow-up .. 39

1

1. Introduction

Injuries in sport are a fact and there has been done much research about the

frequency of injuries in lower extremities. Studies have revealed some ways to

reduce the probability of injuries of lower extremities in sports with

neuromuscular training protocols, but only few have measured performance

parameters as a positive effect of such training.

The world’s most popular sport is football; there are approximately 265

million male and female players who are active in the game of football and 5

million referees and officials. That makes it 270 million active people in the

game of football in 2006. („Big Count“, e.d.). In Iceland there where 32408

players, both male and female, and 1749 referees and officials that where active in

the game of football in the year 2006 („Big Count“, e.d.).

In today society sport play important role and the benefits of physical activity

are well documented, both in youth and elderly people. On the other hand as more

and more people are getting involved in physical activities the number of sports-

related injuries are also increasing (Maffulli, Longo, Gougoulias, Caine, &

Denaro, 2011; Baarveld, Visser, Kollen, & Backx, 2011).

Football is one of the physical activities that sport-related injuries are most

noticeable (Baarveld et.al., 2011). Football is powerful and dynamic sport and

there are high incidents of injuries in that sport (Hawkins & Fuller, 1999;

Hawkins & Fuller, 1996; Baarveld et. al., 2011). Árnason (2008) did a research

where he studied male football players. The most common injury was strain in

muscles; most frequent was hamstring, then groin, ligament injuries, knees and

ankles (Árnason, 2008). In male football were most injuries sprain of ligaments,

sprain of muscles and contusion, but knee injuries were the most severe injuries

like the ACL (Árnason, 2004).

1.1 Injuries in sports

Injuries in sports are different in nature and it depends on the sport and the

combination of intrinsic factor and extrinsic factors. The intrinsic risk factors can

vary from one athlete to another, for example age, flexibility, muscle strength

imbalance, strength, anatomical alignment, neuromuscular control, somatotype,

previous injuries, and more. These factors have a direct effect on the human body.

The extrinsic risk factor is on the other hand outside of the body. Examples of

2

extrinsic factors are playing surface, equipment, and weather conditions. These

risk factors can also change and the athlete can be exposed to different risk factors

throughout time (Meeuwisse, Emery, Tyreman, & Hagel, 2007; Meeuwisse, 1994;

Bahr & Holme, 2003). Meeuwisse (1994, 2007) argued that it was necessary to be

constantly valuating the risk factors. In real live, sports are dynamic and when an

incident happens to an athlete it can alter the sensitivity of an intrinsic risk factor

even if the incident did not reach the calibration of being called injury

(Meeuwisse et.al., 2007; Meeuwisse, 1994).

1.2 Risk factors for ACL and prevention methods

Risk factors for ACL are multiple and there are 0.4 % probability that a

male athlete can rupture the ACL ligament and for women 0.7% probability in

one season (Waldén, Hägglund, Magnusson, & Ekstrand, 2011). The main injury

mechanisms ACL injuries has been proven to be; External rotation of the tibia

with valgus loading while knees are flexing (Koga et.al., 2010; Krosshaug et.al.,

2007; Hewett et.al., 2005), abduction around knee and hip (Hewett et.al., 2005),

increased motion in coronal plain in ankle (Ford, Myer, Toms, Hewett, & others,

2005) and Increased laxity in the knee (Markolf et.al., 1995; McLean, Huang, Su,

& van den Bogert, 2004; Woo, Hollis, Adams, Lyon, & Takai, 1991).

Women are more likely to have ACL injuries than men; they have more

valgus motions, more strain forces on the knee and more anterior shear forces

while they are landing after jumping compared to men (Chappell, Yu, Kirkendall,

& Garrett, 2002; Hewett et.al., 2005). One of the reasons for increased adduction

motion and shear forces on the knee is high angular velocity. Were the hamsrteng

loses part of the abilty to generate power. Women are in greater risk for this

compared to men (Ahmad et.al., 2006; Ford et.al., 2005; Ford, Shapiro, Myer,

Bogert, & Hewett, 2010; Hewett, Myer, & Zazulak, 2008; Hewett, Myer, Ford,

Paterno, & Quatman, 2012).

Research has demonstrated that prevention programs should aim at single

leg jumping and landing techniques, single leg exercises and different strategies

for deceleration techniques, but keep in mind what is best for different sports

(Munro, Herrington, & Comfort, 2012). Prevention programs should also

emphasize on strengthening hamstring and the activation of the hamstring muscle,

to get better dynamic control of the knee. Neuromuscular training could also lead

3

to reduction of ACL injuries, by increasing neuromuscular function that could

improve the biomechanical function of the knee. The neuromuscular adaption

could optimize the reaction time that would provide greater pre-contraction of the

muscles (Ford et.al., 2005; Hewett et.al., 2012; Hewett et.al., 2008; Ahmad et.al.,

2006).

1.3. Hamstrings injuries, risk factor and strengthening

Hamstrings injuries are one of the most frequent injuries in football

(Árnason, 2004; Árnason, 2008). There are number of risk factors that have been

proposed for hamstring injuries, but there are only few of them evidence based.

(Croisier, Forthomme, Namurois, Vanderthommen, & Crielaard, 2002; Petersen

& Holmich, 2005; Opar et.al., 2012; Opar et.al., 2012; Mair, Seaber, Glisson, &

Garrett, 1996; Ekstrand & Gillquist, 1982; Witvrouw, Danneels, Asselman,

D’Have, & Cambier, 2003; Árnason, 2009; Opar et.al., 2012); Arnason,

Sigurdsson, Gudmundsson, Holme, & et.al., 2004; Mair et.al., 1996)

As was indicated above, the risk factors for hamstring injuries are

complex. There are many ways to prevent and rehabilitate hamstring injuries and

all of the risk factors need to be in consideration in the prevention and

rehabilitation programs (Petersen & Holmich, 2005; Opar et.al., 2012). There are

riskfactors for hamstreng injuries were the results of studies has been

controversial like inadequate hamstring muscle length, tightnes and flexibility

(Rolls & George, 2004; Ekstrand & Gillquist, 1982; Meeuwisse & Fowler, 1988;

Witvrouw et.al., 2003; Árnason, 2009).

Studies has argued that Insufficient strength in hamstring could be a risk

factor for injuries in the hamstrings muscle (Hawkins, Hulse, Wilkinson, Hodson,

& Gibson, 2001; Askling, Karlsson, & Thorstensson, 2003; Arnason, Andersen,

Holme, Engebretsen, & Bahr, 2008; Árnason, 2009). There are studies that

support that the Nordic hamstring lowering exercise that strengthens the

hamstring muscle in eccentric and isometric muscles work. There are evidence

that this exercise can reduce injuries in hamstring up to 65% (Árnason, 2009;

Arnason et.al., 2008; Brooks, Fuller, Kemp, & Reddin, 2006).

There are suggestions for relationship between neuronal tension and pain

in posterior region of thigh (Se & Kp, 1998; Kornberg & Lew, 1989). The

4

neuronal adverse tension may be a consequence or be a factor in the etiology of

repetitive hamstring injuries (Se & Kp, 1998). Neuromuscular control of lumbar

movements and pelvic tilt could be an important element in high speed sports like

athletics, football and basketball. This knowledge could be important in

prevention of hamstring injuries and making rehabilitation programs (Cibulka,

Rose, Delitto, & Sinacore, 1986; Hennessey & Watson, 1993).

1.4. Injuries prevention and strength training

There have been many researchers in the field of preventing injuries to

lower extremities in women and men (Petersen et.al., 2005; Lephart et.al., 2005).

Likewise, there has been much research in the field of training exercises to find

out which exercises are the best to produce power for sports that needs speed,

strength, agility, explosive power and jumping (Behrens & Simonson, 2011;

Ebben & Watts, 1998; Markovic & Mikulic, 2010; Myer, Ford, Palumbo, &

Hewett, 2005).

There have many published articles on how to design programs that are able to

reduce the probability of injuries. Most of the results from these studies indicate

that it is necessary that those programs include plyometrics, strength training,

dynamic stabilization and neuromuscular training. Furthermore, combining these

training factors together has revealed promising results (Shultz et.al., 2010;

Hewett et.al., 1999; Hewett, Stroupe, Nance, & Noyes, 1996; Myer et.al., 2005;

Mandelbaum et.al., 2005; Petersen et.al., 2005; Myer, Ford, McLean, & Hewett,

2006; Lephart et.al., 2005; Huston & Wojtys, 1996). Shultz et al (2010) pointed

out that researchers should continue to find new and different prevention

programs and try to identify how much is necessary. For instance, how much

stimulus, how much time? Do the effect last, or is it necessary to do it all the time

(Shultz et.al., 2010).

1.5. Strength training

Studies have shown that strength training extensor muscles in legs

improves power, jumping height and sprinting speed (Manolopoulos,

Papadopoulos, & Kellis, 2006; Fatouros et.al., 2000; McBride, Triplett-McBride,

Davie, & Newton, 2002). Ronnestad, Kvamme, Sunde, & Raastad, (2008) quoted

in Schmidtbleicher in the book Strength and Power in Sport (1992) were he

showed that maximal strength is important to power performance because power

5

is the production of strength and speed. Those who increases one maximum

repetition strength, usually have better probability of increasing power

performance and better ability to make power.

1.6. Plyometrics and strength training.

In most studies that cover this topic is recommended that combination of

strength training and plyometric training could increase power and the ability to

generate power, rather than either plyometric or strength training separated

(Adams, O’Shea, O’Shea, & Climstein, 1992; Fatouros et.al., 2000; Harris, Stone,

Proulx, & Johnson, 2000; Toji, Suei, & Kaneko, 1997). On the other hand it has

argued that it is not necessary to do plyometric strength training when the

footballers are also training football (Ronnestad et.al., 2008).

1.7. Purpose of the study,

The purpose of this study was to add to the knowledge that exists, with

combining different strength training techniques, combine exercises that has

factors like strength, power, stabilization and balance. Such a strength program

that can promote both increase in power, improves strength and reduces the

chance of injury. In this research I will test the effectiveness of specialized

strength training versus normal strength training to prevent injuries and increase

strength and power in elite male football players.

The coach could have a tendency to skip the stabilization and balance

training, when the time is limited per training session. Which is one of the training

factors that are believed to be likely to prevent injuries in the lower extremities?

(Hewett et.al., 2005; Petersen et.al., 2005; Hewett et.al., 1999; Hewett et.al.,

2012).

Looking at the literature, it has not revealed many researches indicating

that specialized strength program can reduce the risk of injuries and also give

similar strength and power benefits as a form of other strength and power

programs. As revealed in the literature injuries in football are complex, some

injuries are more likely to happen in women’s football and some in men’s

football. In this study the focus is on one of the most frequent injuries, like

hamstring injuries but also knee injuries, which is considered to be the one of the

worst injuries for a football player.

6

1.8. Research Question and Hypothesis

I will in this study test my hypothesis; that a specialized strength training

program can increase stabilization and balance, therefore, reduce risk of injury.

Furthermore, it will increase strength and power for the football players just as

well as other strength training programs. The benefit of this kind of a program

over others is that coaches see better performance in strength and power output

whilst performing injury prevention exercises. One of the aims is to motivate the

athletes to do the program since it would improve their performance in sport and

reduce risk of injury.

The following hypothesis will be kept in mind in the process of this

research.

1. Is there a difference in frequency of injuries in lower extremities

between the research group and the control group during the football

season 2013?

a. H1; there will be fewer injuries in lower extremities in the

research group after the football season, compared to the

control group.

b. H0; There will be no difference in frequency of injuries in

lower extremities between the research group and the control

group.

2. Is there a difference in kinematics in lower extremities between the

research group and the control group after the intervention period?

a. H1;The research group is going to have better movement

kinematic on a forward jump landing task in lower extremities,

that is greater flexion angle movement in hips, knee and ankle,

from the lateral view, compared to the control group

b. H1; the research group is going to have less dynamic valgus

moment in the knee from the anterior view, compared to the

control group.

c. H0; there will be no difference in kinematics between the

research group and the control group.

7

3. Is there a difference in speed, power and strength performance

between the research group and the control group after the

intervention period?

a. H1; The research group will have equal or better speed, power

and strength performance after the intervention program, in

mid-season and after the football season, compared to the

control group.

b. H0; There will be no difference between the research group and

the control group.

4. Is there a difference in performance in speed, power and strength

during the intervention and the follow-up through the football season

2013, with in the research group and the control group?

a. H1; The performance in speed, power and strength will increase

during the intervention period, the performance will be the

same or increase in the follow-up throughout the football

season 2013, with in the research group and the control group

b. H0; There will be no difference in performance within the

groups during the intervention period and in the follow-up

throughout the football season 2013.

2. Literature review

In this section I will give a short overview of the literature review. It will

start off with short information on movement of the human body, postural control,

neuromuscular control, and muscle strengthening. Injuries in football, frequency,

mechanism, incidence of common sport injuries and football injuries will be

described. The importance to understand the interaction between different risk

factors for injuries in order to create an effective preventive training program that

can reduce the likelihood of sports injury. Then go on to what have been doing in

the prevention programs, including strength training, neuromuscular training,

dynamic balance training, jumping and plyometric training. The review will also

try to describe what kind of training has been proven to be most effective in

8

strengthening the human body and for producing power in sports that require

speed, strength and power.

2.1. Movement of The Human Body, lower extremities and Postural

Control

The movement of the lower extremities is controlled by certain kinetic

chain. The trunk, hips, knees and ankles are the different anatomical parts of that

chain. To understand the movement of the body, it´s dynamic capabilities and

biomechanical factors that may be part of a previous injury or dysfunction that

can lead to an injury. This can be related to a neuromuscular or muscular

imbalance, anatomical defects like, q-angle of hips, loose ligaments and more

(Griffin et.al., 2006).

To understand the movement of the body, it can be better to break the

body down to simpler or smaller regions for instance: Lumbar-pelvic-hip-complex

or the core. These consist of the lumbar vertebrae, pelvis and hips, and the passive

and active structures that either produce or restrict movement of above mentioned

body segments (Wilkerson, Giles, & Seibel, 2012). Core stability has been

defined as the ability to control position of the core and motion of the trunk over

the legs and pelvis, to allow optimum load transfer, production and control of

motion and force to the terminal elements in the integrated chain activities

(Kibler, Press, & Sciascia, 2006; Wilkerson et.al., 2012).

Maintaining the dynamic joint stability throughout the kinetic chain that

extends from the lumbar spine to the ankles, have been argued to be important

consideration for the concept of core stability. Core stability is an important factor

for preventing injuries (sprains and strains) in lower extremities and core region of

the body (Barr, Griggs, & Cadby, 2007; Borghuis, Hof, & Lemmink, 2008;

Hodges, Richardson, & Hasan, 1997; Wilkerson et.al., 2012). Dynamic is the key

word, when looking at postural control in sports. Most sports are dynamic were

the individual is constantly changing position and direction. The dynamic

postural control involves many levels of movement around the base of support,

like jumping in different directions and keeping the upper body as still as possible,

or different types of agility and movement without compromising the base of

support (Gribble, Hertel, & Plisky, 2012; Herrington, Hatcher, Hatcher, &

McNicholas, 2009; Wikstrom, Tillman, Schenker, & Borsa, 2008).

9

The Muscular system that is attached to the Lumbar-pelvic-hip-complex

can play an important role in postural and dynamic control. Dysfunction of the

lower back, weakness and alterations of neuromuscular activation patterns can

lead to injuries in the core and also in distant joints (Beckman & Buchanan, 1995;

Hodges, 2003). The focus of training the core should be on the deeper muscles of

the lumbar region, the multifidus and abdominal transversus but also on the

general abdominal muscles, paravertebral and gluteal muscles. This is believed to

enhance capability of performance and reduce risk of injuries (Nadler, Malanga,

DePrince, Stitik, & Feinberg, 2000; Wilkerson et.al., 2012; Hodges et.al., 1997).

2.3. Neuromuscular adaption and Muscle Strengthening

There are many factors in the muscular system that is affected when

performing strength training. It is important to understand the adaptation that

exists in the neuronal system when a new movement is learned. The neuronal

Darwian process is theory that describes neuromuscular adaption. How is the

neuronal system able to adapt continuously to different circumstance and

movement over time? The key to functional aspects of this idea is that certain

neuronal pools work together, that are related to specific zones. This depends

essentially on two factors (Tipton & Medicine, 2006). One: Selection of certain

neuronal groups that perform specific motor coordination or motor neuron pattern

is consistently updated from experience of special item or mechanism. Two:

These nerves groups form a specific motion pattern, which is in turn formed by

coordinating selected sensory and motor nerve processes. This idea also assumes

that different neural populations can perform the same process again (Tipton &

Medicine, 2006). When we perform a particular movement, the nervous system

learns how the movement is performed. The nerve messages are received faster,

because the nerve groups that are selected for this particular movement is

activated from a higher motor center and also contributed by sensory nerves in the

area that is being used in the movement (Tipton & Medicine, 2006).

It has also been argued that a motor relearning in the spinal cord can

happen when reflexes are present. This is more relevant for coordination of motor

unit in movement, which attempts to activate aspects of motor neuron populations

with specific exercises to elicit greater coordination of motor nerve groups (motor

pool recruitment (Tipton & Medicine, 2006). Coordination of motor units is one

10

of the primary key to generate power at the right time and under the right

conditions. It has been shown that with specific dynamic training it can improve

this coordination. Studies have demonstrated that there is a greater coordination of

muscles with eccentric muscle work rather than concentric muscle work. It is also

believed that the rate of depolarization can be increased by training and therefore

lead to increased speed to achieve maximum power and increase the maximum

power (Tipton & Medicine, 2006).

2.4. Injuries in football

Football is one of the physical activities that sport-related injuries are most

noticeable (Baarveld et.al., 2011). Football injuries involve many segments of the

body, but mostly in the lower extremities. The severity of these injuries does vary,

from minor injuries that last from 1 day absence from competition to more serious

injuries with absence of 28 or more days from competition, which can end a

football carrier (Fuller et.al., 2006; Rahnama, Reilly, & Lees, 2002; Wong &

Hong, 2005; Engstroem, Johansson, & Tornkvist, 1991; Hägglund, Waldén, &

Ekstrand, 2009; Lüthje et.al., 1996; Hawkins & Fuller, 1999; Hawkins & Fuller,

1998; Árnason, 2004; Hawkins et.al., 2001; Árnason, 2008).

2.4.1. Frequency of injuries in football

When injuries in football are reviewed it is necessary to look at the

frequency of injuries and what kind of injuries are most common and what

injuries are harmful for the athlete/football player. Injuries in Icelandic male

football second and first division and the insides of injuries in football was high in

Iceland (Árnason, 2004; Árnason, 2008). The most common injury was muscle

strains (n=75); the most frequent in hamstring (n=31), then groin (n=22).

Ligament injuries were most common in knees (n=20) and in ankle (n=20)

(Árnason, 2008). In the PhD thesis from Árnason (2004) where he studied

injuries in male football. He found out by reveawing many researches, most

common injuries where ligament sprains, 19-55%, muscle strains 12-37% and

contusions 4-26% other injuries were less significant like fractures and

dislocations. The body segments that are most injured is in this order; first the

ankle, then the knees, thigh, groin, foot, lower leg, back and the lowest of

frequency was the head. On the other hand newer studies have shown higher

proportion of hamstring muscle injuries. But the most severe injuries were knee

11

injuries, and the ACL was the worst, and the football players were longest time

away from training and matches (Árnason, 2004; Waldén et.al., 2011).

In a two year survey from Baarveld et al. (2011), they registered 694

sports-related injuries. They found out that per 1000 patients seen by general

practitioner there was 23.7 incidents of sport-related injuries. They also found

that most of these injuries was from football players (Baarveld, Visser, Kollen, &

Backx, 2011).

When looking at the severity of injuries, researchers have classified how

many days the athlete cannot participate in training sessions, from the time of

injury to the time of fully returning to the sport training. According to Fuller et al

(2006) the time period when a player can participate in a football game or practice

from a following injure? The injury is categorized as a minor, or cero day of

injury, when the athlete is absent for one to three days the injury is called

minimal, four to seven days it is called mild, 8 to 28 the injury is called moderate

and if the injury lasts more than 28 days it is called severe. That kind of injury

can be carrier threatening injury (Fuller et.al., 2006). Over 65% of injuries in

football are classified as mild or minor, 25% of them are moderate and

approximately 10% are classified as severe (Rahnama et.al., 2002; Wong & Hong,

2005; Engstroem et.al., 1991; Hägglund et.al., 2009; Lüthje et.al., 1996; Hawkins

& Fuller, 1999; Hawkins & Fuller, 1998; Árnason, 2004; Hawkins et.al., 2001).

2.4.1.1 Epidemiology of Anterior Cruciate Ligament (ACL) Injuries

As has been mentioned that ACL injuries are relatively uncommon

compared to thigh muscles and ankle strains and sprains, there is a 0.4%

probability that a male athlete can rupture the ACL ligament, and a 0.7%

probability for women in one season (Waldén et.al., 2011). ACL injuries are

common in the USA and it is estimated that over 1, 5 million ACL reconstructions

have been done in the last 20 year. The cost of ACL reconstruction and

rehabilitation is estimated to be around 17000 US dollars. It is likely that the cost

goes over 3 billion US dollars each year in the USA (Kim et.al., 2011; Hewett

et.al., 1999). It has been estimated that 80000 to 250000 ACL ruptures occurs

every year. Around half of them are young people in sports from the age 15 to 25.

Despite surgical stabilization of ACL reconstructive, the posttraumatic arthritis

12

frequently develops in young athletes. Therefore the one of their emphasis was to

improve prevention programs to increase their effectiveness (Griffin et.al., 2006).

2.4.1.2. Osteoarthritis after ACL and meniscus Injuries

Evidence suggests that osteoarthritis can develop 10-14 years after ACL

ruptures in athletes. The probability of osteoarthritis in young women and men

can be up to 78%, 10-14 years after the ACL rupture. It seems that age is a factor,

as athletes over 30 years old have increased risk to get osteoarthritis. Stability

rehabilitation has on the other hand shown that there is a possibility to reduce the

risk of getting osteoarthritis, but it will not prevent it (Gillquist & Messner, 1999;

Lohmander, Östenberg, Englund, & Roos, 2004; Lohmander, Englund, Dahl, &

Roos, 2007; Porat, Roos, & Roos, 2004).

2.4.2. Risk Factors for injuries in lower extremities

Injuries in sports are different in natures and it depends on the sport and

the combination of intrinsic and extrinsic risk factors. The same individual can be

exposed to different risk factors rapidly over time in many similar conditions and

he may and may not get injured? To be able to make a prevention program to

minimize the risk of injuries, the researcher or the coach must examine the many

risk factors that are thought to be prior to the injury (Meeuwisse et.al., 2007).

Sports related injuries are in fact multifactorial. Multifactorial model

(Figure 1) from Meeuwisse et al (2004) attempts to account for the interaction of

multiple risk factors, both intrinsic and extrinsic that interact to make the athlete

more likely to have an injury before the injury actually happens (Meeuwisse,

1994; Meeuwisse et.al., 2007).

Figure 1. Multifactorial model of athletic injuries etiology

13

Meeuwisse et al (2007) outlined a new manuscript; model for more

dynamic approach containing the consequences of repeated participants in sports,

both with and without injuries (Meeuwisse et.al., 2007).

Movement in sports are dynamic and change over time both in the game and in

repeated events over time, and the athletes can be exposed to extrinsic risk factors

repeatedly? They can alter the sensibility to the risk factors. Moreover the athlete

can be exposed to an incident that will not reach the grade of being called an

injury, but still enhance the intrinsic risk factors. Definition of an incident can be

asymptomatic microtrauma that is caused by repeated collision, fatigue in one

football game, or micro trauma to joints or muscle. This can lower strength or

reduce neuromuscular control, and then the athlete may be more predisposed to

injury. These will change the picture for the athlete, even if most of other

elements and the environment may remain constant. Meeuwise et al (2007)

believed that the new model, dynamic recursive model of sport injuries (figure 2),

could be more effective in understanding the etiology of injuries and the

researchers could be more effective in targeting the appropriate preventions

strategies. Were the incident in a sport event may cause injuries to happen, or it

may not have any traumatic effect. But still it alters some of the intrinsic factor

that may cause an injury later or in the same sports event or the next. It can also

have the effect, that adaption occurs and the athlete is better prepared for the next

incident. As previously stated, sport is dynamic in real live, also the athlete and

the risk factors, both intrinsic and extrinsic factors. So there is a need to be

constantly evaluating the risk factors, both when injuries happen and also in the

absence of injury (Meeuwisse, 1994).

14

Figure 2. Dynamic recursive model of sport injuries (Meeuwisse et al., 2007). Intrinsic and extrinsic

risk factors.

Every athlete has his own set of intrinsic risk factors that can vary from,

for example age, flexibility, muscle strength imbalance, strength, anatomical

alignment, neuromuscular control, somatotype, previous injuries, and more.

These factors have direct effect on the human body. But extrinsic risk factors are

outside of the body. For example playing surface, equipment, and weather

conditions (Meeuwisse et.al., 2007; Meeuwisse, 1994; Bahr & Holme, 2003b).

2.4.2.1 Risk Factor for ACL Injuries

There are many known risk factors concerning the ACL like increased abduction

motion torque in the knee, increased valgus motion of the knee and hip, anterior

shear forces, decreased ability to produce force at high angular velocity in the

hamstring muscle and the sequence of timing and ratio between hamstring and

quadriceps muscles (Ford et.al., 2005; Hewett et.al., 2012; Hewett et.al., 2008;

Ahmad et.al., 2006; Munro et.al., 2012). Increased motion of the ankle in coronal

plain in jumping and landing could also been related to increased risk of ACL

injuries in women (Ford et.al., 2005). It has been predicted that ACL Injuries are

more likely to happen when there is increased motion inside the knee joint

(Markolf et.al., 1995; McLean et.al., 2004; Woo et.al., 1991). Many researchers

agree that female, after puberty and in the early adulthood, have more risk of ACL

injuries than men (Ford et.al., 2005; Hewett et.al., 2012; Hewett et.al., 2008;

Ahmad et.al., 2006). As said above the adduction and dynamic knee valgus can be

related to injuries in lower extremities, it should be symmetrical for unilateral step

15

landing task. The valgus angle in the knee should be in the range of 1-9° for men

and 5-12° for women (Herrington & Munro, 2010). If the knee is nearly fully

extended there is a greater risk of ACL injuries (DeMorat, Weinhold, Blackburn,

Chudik, & Garrett, 2004).

It has been predicted that women are in 5.3 times more relative greater risk

of sustaining a valgus collapse than male players have greater hip and knee

flexion than men in landing task (Koga et.al., 2010; Krosshaug et.al., 2007).

Women have more valgus motion, strain forces (Chappell et.al., 2002; Munro

et.al., 2012) and more anterior shear forces in lower extremities while they are

jumping and landing than men (Chappell et.al., 2002). There fore they need more

stabilization training and preventions training than men (Hewett et.al., 2005;

Waldén et.al., 2011).

Many studies argue that prevention programs should emphasize on

strengthening hamstring and the activation of the hamstring muscle, and therefore

to get better dynamic control of the knee. Neuromuscular training could also lead

to reduction of ACL injuries, by increasing neuromuscular function that could

improve the biomechanical function of the knee. The neuromuscular adaption

could optimize the reaction time that would provide greater pre-contraction of the

muscles (Ford et.al., 2005; Hewett et.al., 2012; Hewett et.al., 2008; Ahmad et.al.,

2006; Munro et.al., 2012; Ford et.al., 2010). It has also been suggested that

prevention programs should aim at good landing and cutting technique, without

valgus loading, with the knees in a flexed position (Koga et.al., 2010; Munro

et.al., 2012).

2.4.2.2 Risk factors for Hamstring strain.

As mentioned, hamstring injuries are one of the most common injuries in

football (Árnason, 2008; Ekstrand, 2008; Árnason, 2004; Petersen & Holmich,

2005; Hauge Engebretsen, Myklebust, Holme, Engebretsen, & Bahr, 2010). It has

been demonstrated that hamstring injuries account for 12-16 percent of all injuries

in Australian and English football (Petersen & Holmich, 2005). It has been

estimated that hamstring injuries cost 74.4 million pounds in premier and other

football league clubs in English football in one season 1999 to 2000. In Australian

football, the cost was estimated in to be around 1.5 million dollars in the 2009

16

season (Opar et.al., 2012). There are a number of risk factors for hamstring

injuries but there are only few which are evidence based. Risk factors include

muscle imbalance, H/Q ratio (Croisier et.al., 2002; Petersen & Holmich, 2005;

Opar et.al., 2012), muscle fatigue (Petersen & Holmich, 2005; Opar et.al., 2012;

Mair et.al., 1996), tightness of the hamstring muscle (Ekstrand & Gillquist, 1982;

Witvrouw et.al., 2003; Árnason, 2009; Petersen & Holmich, 2005; Opar et.al.,

2012), prior injuries (Petersen & Holmich, 2005; Arnason et.al., 2004; Opar et.al.,

2012; Hauge Engebretsen et.al., 2010) and insufficient warm-up (Petersen &

Holmich, 2005; Mair et.al., 1996). The risk factors of hamstring injuries are

complex. There are many ways to prevent and rehabilitate hamstring injuries and

all of the risk factors need to be considered for in the prevention and rehabilitation

programs (Petersen & Holmich, 2005; Opar et.al., 2012).

2.4.2.2.1 The length and laxity of hamstring

Inadequate hamstring muscle length has been thought to be a risk factor

for injuries in the muscle but results has been controversial. Rolls et al (2004)

found out that there was no connection between hamstring injuries and length of

the hamstrings muscles and they concluded that the length of the hamstring

muscle was not a predictor of injury (Rolls & George, 2004). This finding is

similar to other researches (Meeuwisse & Fowler, 1988; Ekstrand et al., 1982).

Ekstrand et al (1982) examined 180 soccer players and found no relationship

between muscles tightness in lower extremities and injuries (Ekstrand & Gillquist,

1982). Studies on the other hand have shown relationship to hamstring flexibility

and higher risk of injuries. According to Witvrouw et al (2003) an increased

tightness in hamstring or quadriceps muscles have a higher risk of

musculoskeletal lesion (Witvrouw et.al., 2003). The role of flexibility in

hamstring muscles regarding injuries is unclear and the evidence is less

convincing (Árnason, 2009).

2.4.2.2.2. Insufficient strength and muscle imbalance in hamstring as a risk factor

In recent years it has been believed that insufficient strength in hamstring

could be a risk factor for injuries in hamstring (Hawkins et.al., 2001; Askling

et.al., 2003; Arnason et.al., 2008; Árnason, 2009; Opar et.al., 2012). The Nordic

hamstring lowering is an exercise that has become a popular exercise that

strengthens the hamstring muscle in eccentric and isometric muscles work

17

(Árnason, 2009). There have been studies that supports that the Nordic hamstring

lowering exercise can reduce injuries in hamstring up to 65% between football

teams that used the exercise compared to teams that did not use this exercise

(Arnason et.al., 2008). In another study the participants where split into three

groups. One group did strength training alone, the second group did strength

training and stretching, and the third group did strength training, stretching and

the Nordic hamstrings lowering exercise. The results were that the third group had

the lowest incidents of hamstring injuries during matches and training (Brooks

et.al., 2006).

H/Q strength ratio has been studied and there are evidence that supports

that insufficient ratio could be a risk factor for hamstring injuries (Croisier et.al.,

2002; Petersen & Holmich, 2005; Opar et.al., 2012). Muscle imbalance between

right and left leg has been thought to be predictor for hamstring injuries but some

authors have found that there is no predictive power for bilateral strength

imbalance (Opar et.al., 2012).

2.4.2.2.3. Other risk factors for hamstring injuries.

There has been some believe that anatomical factors can be a predictor for

hamstring injuries. These factors are like differences in muscle fiber, differences

in neuronal stimulation, different innervations from different neuronal fibers to

different aspects of the hamstring muscle and anterior pelvic tilt recording to

lengthening of the hamstring muscle (Opar et.al., 2012). There is suggestion for

relationship between neuronal tension and pain in posterior region of thigh (Se &

Kp, 1998; Kornberg & Lew, 1989). According to Turl et al (1998) the neuronal

adverse tension may be a consequence or be a factor in the etiology of repetitive

hamstring injuries (Se & Kp, 1998). Neuromuscular control of lumbar

movements and pelvic tilt could be an important element in high speed sports like

athletics, football and basketball. This knowledge could be important in

prevention of hamstring injuries and making rehabilitation programs (Cibulka

et.al., 1986; Hennessey & Watson, 1993). Acording to Cibulka et al (1986)

patients that have experienced hamstring strain and were treated by correcting the

dysfunction in the sacral-iliac joint, they had greater force in their injured

hamstring muscle than the patients that had no correction of the sacral-iliac joint

(Cibulka et.al., 1986). It has been argued that fatigue is a predictor for hamstring

18

injuries. When the muscle gets fatigued, the capacity of lengthening reduces and

the muscles are more likely to sustain strain injuries (Petersen & Holmich, 2005)

2.5. Risk Factors and Prevention Methods

In a meta-analysis from Shultz et al. (2010), there are mentioned many

mechanical risk factors that have been mapped and intervention programs that are

specialized for prevention seem to reduce the risk factors. These programs include

plyometric, strength training, dynamic stabilization and neuromuscular training.

But there is some evidence that the intervention programs are transient (Shultz

et.al., 2010). Researchers have been developing methods that reduces the risk of

ACL injuries and studies have shown that there is a relationship between the

mechanism of the lower extremities and the noncontact ACL injuries. This has led

to developing specialized programs to reduce the risk of ACL injuries, more for

women than men. These programs where developed by coaches and researchers

that have trained and studied women's dynamics (Hewett et.al., 1999; Hewett

et.al., 1996). Newer studies tend to use similar approach that has been developed

from injury mechanism and training research, by combining many factors of

plyometric and dynamic balance exercises. These exercises can reduce valgus

motion in ankle, knee and adduction in hip and further more sports that requires

increased knee flexion’s movements that it could be necessary to practice both

plyometric and dynamic balance exercises (Myer et.al., 2006; Myer et.al., 2005;

Mandelbaum et.al., 2005; Petersen et.al., 2005).

Research has demonstrated that increased knee flexion can give the

hamstring a better torque and then a better support for the ACL (Huston &

Wojtys, 1996; Hirokawa, Solomonow, Luo, Lu, & D’Ambrosia, 1991). Increased

muscle activity in gluteus medius can improve stabilization in the knee by

reducing adduction movement in the hip (Chimera, Swanik, Swanik, & Straub,

2004). The neuromuscular and biomechanical characteristic changes in training,

has been demonstrated in both basic strength training and plyometric training. The

effects are increased strength in quadriceps muscles, increased knee flexion in

touch with the ground and the maximum flexion in the landing and increased

muscle activation in gluteus medius (Lephart et.al., 2005; Huston & Wojtys,

1996). But the difference between basic strength training program and plyometric

program is that, there can be better coordination of hamstring muscles activation

19

with plyometric training. This could increase stability of the knee and hip by

stabilizing the knee for internal/external rotational torque (Lephart et.al., 2005). It

has been argued by other researches that increased hamstring activity would

decrease the risk of ACL injuries (Nagano, Ida, Akai, & Fukubayashi, 2011;

Besier, Lloyd, & Ackland, 2003). Shultz et al (2010) pointed out that researchers

should continue to find new and different prevention programs and try to identify

how much is necessary. For instance how much stimulus, how much time and do

the effect last, or is it necessary to do it all the time (Shultz et.al., 2010).

It has been revealed that there are many risk factors for hamstring injuries

and the prevention programs or exercises should emphasize strengthening of

hamstring, especially eccentric strengthening (Petersen & Holmich, 2005; Opar

et.al., 2012; Árnason, 2009; Arnason et.al., 2008). Stretching is also thought to

be preventive for hamstring injuries even if there is lack of evidence that tight

hamstring is a predictor for hamstring injuries (Opar et.al., 2012; Árnason, 2009).

Physical conditioning has also been a factor for hamstring injuries because of

fatigue in the muscle. The capacity of lengthening reduces and the muscles are

more likely to sustain strain injuries (Petersen & Holmich, 2005; Opar et.al.,

2012). Neuromuscular training is also considered to be good for reducing the risk

of hamstring injuries. The training should be for many parts of the body,

especially for lumbar-pelvic complex, hamstring and other muscles of the lower

extremities but there are more work needed in this area of research (Se & Kp,

1998; Kornberg & Lew, 1989; Cibulka et.al., 1986; Hennessey & Watson, 1993;

Opar et.al., 2012).

2.6. Different Strength Training for football and other sports

As mentioned above, research has demonstrated that many different

exercises can reduce the risk of injuries in lower extremities. But are these

exercises fulfilling the demands of the sport, for instance providing the power and

strength that is necessary for a professional level, like professional football,

basketball and other professional sports? Is there a high demand of speed,

explosive power, agilities and strength? Or is it necessary to do other exercises

for that?

20

2.6.1. Strength Training

Research has shown that strength training targeted at extensor muscles in

legs improves power, jumping height and sprinting speed (Manolopoulos et.al.,

2006; Fatouros et.al., 2000; McBride et.al., 2002). Ronnestad et al. (2008) quoted

in Schmidtbleicher in the book Strength and Power in Sport (1992) were he

showed that maximal strength is important to power performance because power

is the production of strength and speed. Those who increase 1-RM (one

repetitions maximum) strength, usually have better probability of increasing

power performance and better ability to make power (Ronnestad et.al., 2008).

2.6.2. Strength Training, Plyometric and Balance Training.

Studies have demonstrated that professional football players that do

strength training two times a week can increase one repetition (1-RM) strength,

jump height and time in 10 and 20 meter sprinting (Helgerud, Kemi, & Hoff,

2003). Also there are researches that support the theory that plyometric training

increases power either with or without resistance, in jumping height and sprinting

speed (Wilson, Newton, Murphy, & Humphries, 1993; Fatouros et.al., 2000;

Rimmer & Sleivert, 2000).

In most published studies that cover this topic it is recommended that

combination of strength training and plyometric training could increase power and

the ability to generate power, rather than either plyometric or strength training

alone (Adams et.al., 1992; Fatouros et.al., 2000; Harris et.al., 2000; Toji et.al.,

1997). The study from Lytte et al. (1996) were their goal was to find a short

training program that would be the best to achieve performance in dynamic

exercises like running, jumping, throwing and cycling. There was not a valid

difference between groups. However the combined training group did show a

better performance in the dynamic sports, like running, jumping, throwing and

cycling. This applies primarily to exercises that are based on stretch-shortening

cycle in muscles (Lyttle, Wilson, & Ostrowski, 1996).

Ronnestad et al (2008) studied a different approach for strength training

for football players. The exercises that they studied were maximum strength

training, maximum strength and plyometric training and control group that did

balance training and stretching. No difference was between the research groups.

But the research groups had a valid better performance in most of the test,

21

compared to the control group, aside from 20m sprinting and the counter

movement jumping there were no difference. The conclusion was that it is not

necessary to do plyometric strength training for football players when they are

also training football (Ronnestad et.al., 2008). Different results from other

research implicate a valid difference between groups that did maximum strength

training for one group, and plyometric and strength training for other group. It is

argued that strength training should be performed in combination with jump

training (Harris et.al., 2000). In research that was done by Barber (2010), their

purpose was to find out the best training and testing protocols that could be done

on the tennis court for tennis player. They found out that neuromuscular training

like plyometrics, jump training, strength training with light weights and specific

drills for tennis did increase performance in the entire performance test with an

intervention program for 6 weeks (Barber-Westin, Hermeto, & Noyes, 2010).

2.6.3. Low Intensity Plyometrics.

Rubley et al (2011) studied low-impact and low-frequency plyometric

training, were the participants were 16 female adolescents that played football.

The participants were divided into two groups; experimental group that had an

extra plyometric training session once a week and a control group that trained

normally their football practices. They measured vertical jump and kicking

distance. The group that trained with low- frequency and low- impact plyometric

training had significantly higher vertical jump and kicking distance compared to

the control group. They emphasized that this kind of training could be beneficial

to strength and conditioning coaches, instead of training plyometric with high

impact and high intensity (Rubley, Haase, Holcomb, Girouard, & Tandy, 2011).

There are several studies on exercises that can increase strength, power,

speed and stabilization in muscles and joints. But there is a shortage of research

that show that specialized strength and power program, where the stabilization is

brought into the strength training. We have therefore designed a program of

complex training involving strength, balance and low-frequency plyometric. With

the aim to reduce both the risk of injuries and provide a similar strength and

power output as a basic strength and power traning programs would do.

22

3. Methods

3.1. The Participants

The participants were selected from two football team in the Icelandic

premier division, within the city limits of Reykjavik. There were 23 males in the

research group and 23 males in the control group, The inclusions criteria for the

participants were male over 18 years, healthy and ready to play football match at

start of the study. Exclusion’s criteria were players younger than 18 years old and

players from these teams that have had severe injury 6 months prior to the study.

The participants gave their written consent (appendix 7.1) to participate in the

study after they had been given information about the study procedure (appendix

7.2). Partnership statement from the football club was also obtained (Appendix

7.3).

Confidentiality and personal information were secured by assigning each player a

unique code number. The National Bioethics Committee was informed and

provided permission for the research (12-184-S1), Also, the Data Protection

Authority was informed. All the participants give their permission to use their

data in the study.

3.2. Measurement Instruments

Two times two dimensional

kinematics (2D)

Two high speed cameras

Casio EX-FH25 (Casio America

INC) were used in this study one

was located 3.20 m in front of the

testing area for frontal view. The

other was located 3,20 m to the

side for sagittal view. When the left leg was being

tested, the camera was on left side and on the right side respectively. The cameras

were adjusted in 80 cm height from ground. Sampling rate was 120 frames per

second (fps) for both cameras. To be able to synchronize the videos for data

evaluation and analyzing a custom made flash light sync box, from Kine (Kine

Figure 3 Sync box

23

ehf, Reykjavik, Iceland) (figure 3) was used. The light on the sync box was seen

by both cameras and turned off when the test started.

Physical parameters: sprinting, jumping and strength.

In a 30 meter sprint task: Electrical timing was done with Micro-gate

RACETIME 2. (Microate S.r.l. Bolzano, Italy) There were two gates with one

photo-cell in each. The gate was 150 cm wide and placed 30 meters a part. The

photo-cells were placed on a tripod in a 120 cm height.

Max vertical jump: Height was measured with KineJump, acceleration

meter and KineJump program for PC-computers (Kine ehf).

The maximal strength test: Strength was measured with a squat stand,

Olympic weight bar (20 kg) and sets of barbells from 2.5 kg to 20 kg.

Digital data from the mesurements and all the computer programs were

stored on Pacard Bell laptop computer (Paccard bell, China).

3.3. Procedure

Anthropometric data, (age, height and weight) were obtained from all the

participants and then they were divided into two groups. The first group (research

group) got a specialized strength training program (the intervention). The second

group (control group) did their normal strength training and prevention exercises

that the coach of the control group designs, without any knowledge from the

researcher.

The research was split into few components. The hypotheses were tested

by analyses of risk factors in lower extremities with forward jump lunge test. The

physical performance was tested with maximum speed test, maximum vertical

jump test and maximum strength test. The sequence of the tests and which

measurement was taken in every test during the study are shown in table 1.

24

Table 1. Test sequence in the study

The first test (M1) was performed before intervention period in February

2013, the second was performed after the intervention period (M2) in april 2013.

In the follow-up there were two tests; test 3 (M3) was performed in the middle of

the football season in june/july 2013 and in end of the football season the test 4

(M4) was performed in end of september 2013. In the time table (Figure 4) is

shown when all of the tests were performed

Figure 4 Time table for the research

Like said before, the tests on the participants are done 4 times before and after the

intervention, in the midseason and then at the end of the season. This was done

like this, to be able to measure the training factor both straight after the

intervention and then again in the midseason. The last measurements are to

measure the consistency of the training factors throughout the football season. The

implementation of test measurements are shown in detail in Table 2 and forward

Before and after intervention periode Test that were taken

Measurement in test 1 and 2 (M1 and M1)

kinematic measurements: Forward jump test (hop lounge) 30 meter speed test Max Vertical jump test Max strength test

The follow-up Test that were taken

Measurement in test 3 (M3) Max Vertical jump test

Measurement in test 4 (M4) 30 meter speed test Max Vertical jump test

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Measurements M1

intervention

intervention

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Measurements M2

follo up

follow up in season

Measurements M3 og M4

analyzing

writing the theses

reviewing

reviewing

writing a reticule

25

jump is also shown in Figure 7. The warm-up before the tests was not

standardized, but all participants did warm-up for approximately 10 minutes

before all the tests. Before the 30m sprint test, they did two to four acceleration

sprints up too max speed for 50m. The time that it took to do the tests, the

intervention program and the follow up, should not be more than 8 months. The

analysis of the data should not last for longer time than 8 weeks (Figure 4). Not all

of the participants were able to take all the tests. In Figure 5 the dropouts for the

research group are outlined and explaned and for the control group in Figure 6

Figure 5. Dropouts during the study for the research group.

Figure 6. Dropouts during the study for the control group

26

Table 2 Desciption of every test taken in the study

Tests Description and Parameters obtained in measurements

30 merter speed test A 30 meter sprint is executed while the time is recorded. This is done by using electrical timing with photocells (Micro-gate RACETIME 2. (Microgate S.r.l.). The photocells detect motion at the start and stop when the runner starts from a standing position 50 cm from the first gate, goes through the first gate which sets time on and runs as fast as he can through the second gate which stops the time. Participants have warm as mentioned up with two trial runs before the test. Every Participant runs three times and then the mean of the three runs are calculated. The mean speed was used in the study, trying to relate to consistence in speed for many repetitions like in the football game. The 30 meter speed test was selected because 96% of all sprints in football are shorter than 30 meter (Stølen et.al., 2005).

Max Vertical jump test Max vertical jump, was performed with Counter movement jump: To measure this, a motion sensor (kinejump) is used from the company KINE ehf. The participants train three times before the max jump test. The participants jump three times with five second interval during the max vertical test and then the mean is calculated. In the beginning the test is explained to the participants. Start position; stand straight in a relaxed position, put the arms on the hips and kept still throughout the jumps. Counter movement jump is then executed by and the participant instructed bend the knees and hips without stopping and then jump as high as they can do for every trial. Max vertical jump test( Counter movement jump) was selected to measure power because it has been proven that vertical jump height can reflect strength and power in lower extremities (Bosco, Luhtanen, & Komi, 1983; Harman, Rosenstein, Frykman, & Rosenstein, 1990). Power has been found necessary in throwing, jumping, changing directions and accelerations and all of the above mention parameters are elements in football (Meylan et.al., 2009).

Max strength test Squats: Three reps maximum strength (Kg). Relative strength was calculated by dividing participants max weight in squat with his body weight. Before the test participant did warm-up as described earlier. After that the test began. Weights were put on the weight-lifting bar, and then gradually increased until the participant could not perform more three repetition max. The participants took as many sets as they needed until they could not perform any more (the range was 5 to 7 sets). The rest interval between sets was full rest or approximately 3 min. The squat test was selected for strength because the Maximal squat strength is in strong correlation to sprint performance in elite soccer players (Stølen, Chamari, Castagna, & Wisløff, 2005)

For kinematic

measurements Forward

jump test (hop lounge)

To measure this, hop lunge was used with protocol from Whatman (2011), where the participants will start in a shoulder wide double leg standing. The participant was instructed to jump after the researcher turn of the sync box light. They will jump forward approximately one meter and land on a single leg, the participants were instructed to continue squatting until balance is reached and try to hold the balance for at least 5 sec. (Figure 7) After that the participants can return to the start position. The test is repeated two times for both legs, started on the right foot twice and then left twice . Before the test, the participants have practice session, three times for both legs (Whatman, Hing, & Hume, 2011). The jump-lunge test has been used to measure balance for football players (Stølen et.al., 2005)

27

Figure 7 the forward jump test (hop lunge)

To analyze the kinematics, two high speed video cameras were used to

record data (Figure 7). Prior to the tests, markers were placed on anatomical

landmarks aiding with the evaluation of recorded data. Markers placement were

on metatarsal five, malleolus lateralis, midpoint ankle (between the lateral and

medial malleol), middle of patella, head of fibula, lateral condilus of femor,

trochanter major of femur, anterior superior iliac spina and lateral crista ilium, as

shown in figure 8.

Figure 8 marker placement

3.3.1. The intervention training program

The intervention was a specialized strength training program for the

research group but the control group went through a basic strength training

program with ketlle-bells. The researcher did design the specialized strength

training program designed for the intervention group, but the strength training

program for the other football team (control group) was designed by the coach of

28

that team. This was done in this manner to remove doubt. That is to say, if the

researcher could make both programs that the strength programs would be

designed to get a favorable result. But the researcher did overlook both the

programs for the research group and the control group to prevent that they were

too similar.

The specialized strength training program was designed in that way that

exercises might reduce risk factors for injuries in lower extremities, improving

stability in core and lower extremities, but also increases strength. For example,

single leg squat, clean on one leg, step-ups with moving weights and agility

training with plyometric. The program is shown in appendix 7.4 with the annual

plan, mesocycle, and pictures of exercises. The strength training program for the

control group was done with kettle bells and other strength conditioning training,

like single and double leg squats with kettle bells, snatch and clean with kettle

bells and so on. The outline of the program is shown in appendix 7.5.

The intervention programs lasted 5 weeks. Exercises sessions were 3

times a week and every training session took between 60 to 90 minutes depending

on the size of the group that was training at any time. The researcher was on every

strength training session in the intervention period. After the intervention

program the researcher did a follow up program to the beginning of the season

and then through the whole season. The training sessions were twice a week in

the period to the start of the football season and then one to twice a week through

the season, depending on the frequency of the football games. The researcher

instructed strength training ones a week, the coach instructed the second, until the

mid-season, then the coach took over to the rest of the season. At that time the

strength training sessions were shorter up to 30 min with fewer exercises and

fewer reps. The changes in the strength training programs from the intervention

programs to the preseason program and then program during the season are shown

in appendix 7.6.

The coach of the control group did get freedom to decide how much time

he normally spends on strength training and stabilization training, as well how

many training session he thinks that is necessary to get the results that he wants.

The strength training program lasted from February 2013 to end of April 2013.

There were two strength training sessions per week, as well as one extra strength

training sessions were the football player’s worked on their own. The

29

stabilization exercises were in the normal football training session in the warm-up.

The strength training during the summer for the control group, were also involwed

in the football training session if there was time to do it. The researcher designs

the specialized program which was aimed to get similar results in strength and

power output as the basic strength program but also will reduce the risk factors for

injury. This program did not have separate balance and stabilization program. The

exercises were designed to both increase stabilization, strength and power output

at the same time.

3.3.2. Injuries registration.

The history of injuries was gathered from the participants with

questionnaire before the study began (appendix 7.7). The registry of injuries

during the competition priod 2013 was gathered from the participants after the

season with questionnaire. The questioner is shown in appendix 7.8.

The injuries are broken down into classes according to Fullers et al (2006)

classification system. A cero day of injuries is minor, when the athlete is absent

for one to three days the injuries are called minimal, four to seven days it is called

mild, 8 to 28 days the injuries are called moderate and if the injuries last more

than 28 days they are called severe. That kind of an injury can be a carrier

threatening injury (Fuller et.al., 2006). Engebertsen et.al (2010) used also this

classification for their study on football players (Engebretsen et.al., 2010)

Due to the low number of participants that sustained prior injuries before

this study and then during the season 2013. The type of injuries from the

participants was put in categories. low back, hip and thigh - knee - lower leg and

foot - other injuries: Injuries in the iliopsoas, gluteus maximus area, hernia,

hamstrings, quadriceps and groin strains and low back were classified as low

back, hip and thigh. Everything related to knee classified as knee injuries. Injuries

to the toes, fibula, anterior tibia and shin splint and calf injuries were classified as

lower leg and foot injuries. Injuries that were classified as other injuries were

dislocation to the shoulder, head injuries, broken bone and contusion to the leg.

3.4. Data Process

The data was collected from all the tests, both before and after the intervention

program M1 and M2, the test in midseason and the test after the season M3 and

30

M4. To measure the chances in performance after the intervention period; the

difference in performance were calculated between the test M2 – M1 (M2-M1 =

Diff). The calculation for the difference between measurements M2, M3 and M4

were done in the same way as the calculation as described for M1 and M2. The

number that represented the Diff was used to compare the groups to gather. For

the kinematics; if the number (M2-M1 = Diff) is negative then there is a reduction

of the flexion motion or increase in valgus motions that are being measured. But if

the number is positive there is increase in flexion motion or reduction in valgus

motion.

Also the injuries that were recorded from the participants both prior to the study

and then the injuries during the football season. The data was processed with

statistical analysis.

3.4.1 Analysing of anthropometric data and performance parameters

Mean age with (SD), weight with (SD), height with (SD) and normal

distribution of the groups were computed. Relative strength parameters were used

in statistical analyses and calculated by dividing participants max weight in squat

with his body weight. The mean power production was calculated in jump height

with (SD) for both groups to determine if there is a difference between the groups.

The mean speed with (SD) was calculated within both groups. That data is then

used to see if there is a difference between the groups.

Kine Pro (version 3.2.481, www.Kine.is) from Kine ehf were used to

evaluate kinematics. The goniometer in the Kine Pro was used to find angle size

for valgus in knee and flexion hip, knee and ankle (Figure 9). As has been said

before, that was done by placing marker on certain anatomical landmarks (Figure

8) and calculating the mean difference in valgus motion of the knee, the mean

difference in flexion around the hip, knee and ankle. This was then used to

compare the difference between the groups. This is done in the forward jump

(lunge jump). The measurements were done in three different positions. First the

Base station, that is the start position described in Table 2 (Participants start in a

shoulder wide double leg standing). Second is the Contact, which is when the foot

of the participant touches the ground. Third the Max flexion, when the participant

is in max flexion around knee after he landed and is in balance.

31

Figure 9 Analyzing angles of hip, knee and ankle

3.4.2 The history of Injuries.

The injuries were broken down in classes according to Fullers et al (2006)

classification system, as mentioned before. This was then summarized and the

frequency and the severity calculated so the two groups could be compared

together.

3.5. Data Analysis

SPSS statistics, version 20.0, was used for all statistical analysis, p value <

0.05 was considered statistically significant in this study. Normal distribution

continues variables were checked with kurtosis and skewness. ANOVA was

used to compare the groups togather, in the speed, power and strength and

kinematic measurements. The Levenes test was used to check if homogeneity of

variance was violated in every comparison. To find out if there was a difference

in measurement within groups, between speed, power and strength performance,

before and after the intervention period and follow-up throughout the season

2013. ANOVA for repeated measurements were used to identify whether there

was variability in the tests. To find out if the was a difference in between the

groups related to frequency of injuries, Chi-spuare test (x2) was used to compare

the frequency of injuries between groups.

All data that have personal information like injuries, illness and other

delicate information were stored in such a way that it would not be possible to

connect it to the individuals who participated in the trials. All sensitive data will

be encrypted or deleted after the research. All personal data will be confidential.

32

4. Results

4.1. Participation in measurements and the configuration of the

participants

In Table 4 are the information present for means and standard deviation

(SD) of the variables that were measured in this study. There were 23 males in

the research group, mean ages was 21.96 (SD = 3.6) year, the mean height was

180.6 (SD = 5. 5) cm, and the mean weight was 76.2 (SD = 8.1) kg and 23 males

in the control group, mean age was 22.71 (SD = 4.6) year, the mean height was

180.0 (SD = 6.2) cm, and the mean weight 78.7 (SD = 6.4) kg. The comparison

of the groups was calculated before the intervention periode, to see if they were

homogeneous.

As shown in Table 4 there was no significant difference between the

groups, either in age, height, weight, speed, maximum jump height, strength or

frequency of previous injury. But there were significant differences in three of the

kinematic tests between the groups. Change in knee flexion on left leg, from a

base station to max flexion in landing task (F = 12.95, P = 0.002). Change in knee

flexion on right leg from a base station to contact. (F = 10.04, P = 0.004). Change

in ankle flexion on left leg from a base station to max flexion (F = 6.32, P = 0.02).

There was no significant difference between the groups for rest of the kinematics

tests. Despite of the difference between groups on these three variables, the

groups were considered homogeneous except for these three variables, were the

research group has greater flexion motion in knee and ankle in these variables.

33

Table 3. Mean differences between the groups

Table 4 show the frequency of previous injuries before the study, where 17

of the participants in research group answered the questionnaire for previous

injuries and 23 participants answered the questionnaire from the control group.

The statistic are from both the regions of the body and the severity measured in

days that the football player was absent from training and competition. The total

days absent from practice and competition in each category is also calculated. As

seen in Table 3 the most frequent injuries was to the low back hip and thigh 40%,

then lower leg and foot 30%, knees were 20% and the least were other injuries

10% for both groups.

Table 4 Frequency of previous injuries and the players that did not get injured

N mean SD N mean SD F Sig.

Age 23 21.92 3.6 23 22.71 4.6 0.495 0.485

Height 23 180.6 5.5 23 180.3 6.2 0.39 0.844

Weight 23 76.2 8.1 23 78.7 6.4 1.8 0.186

Max speed. 30 meter19 4.19 0.12 18 4.24 0.15 1.26 0.68

Max Jump 15 41.42 5.49 15 44.29 5.46 2.04 0.65

3X Max strength/Weight 16 1.54 0.16 16 1.49 0.44 2.8 0.1

VM-BC-LF 11 0.96 3.43 13 -0.25 3.62 0.645 0.431

VM-BM-LF 11 -4.29 10.56 13 -3.60 8.31 0.028 0.868

VM-SM-LF 11 -4.13 10.10 13 -3.80 9.20 0.006 0.938

VM-BC-RF 11 -0.54 3.33 13 -2.60 4.64 1.467 0.240

VM-BM-RF 11 -4.83 16.71 13 -12.05 9.89 1.438 0.244

VM-SM-RF 11 -4.29 15.73 13 -9.65 9.06 0.905 0.353

hip: CF-BC-LF 11 35.27 9.01 13 35.27 9.01 0.000 0.995

hip: CF-BM-LF 11 63.45 10.77 13 63.45 10.77 0.483 0.495

hip: CF-SM-LF 11 28.18 10.51 13 28.18 10.51 0.603 0.447

hip: CF-BC-RF 11 35.64 8.19 13 35.64 8.19 0.001 0.979

hip: CF-BM-RF 11 65.09 14.40 13 65.09 14.40 0.669 0.424

hip: CF-SM-RF 11 29.23 14.65 13 29.23 14.65 0.293 0.594

Knee: CF-BC-LF 11 17.00 7.77 13 11.05 8.52 2.803 0.110

Knee: CF-BM-LF 11 61.41 10.23 13 46.60 8.47 12.905 0.002*

Knee: CF-SM-LF 11 44.41 11.48 13 37.80 12.89 1.546 0.229

Knee: CF-BC-RF 11 16.09 6.10 13 7.95 5.40 10.401 0.004*

Knee: CF-BM-RF 11 48.00 10.85 13 53.00 8.14 1.402 0.251

Knee: CF-SM-RF 11 47.55 10.36 13 45.05 7.98 0.376 0.547

Ankle: CF-BC-LF 11 -5.95 16.46 13 -0.95 20.10 0.393 0.538

Ankle: CF-BM-LF 11 28.18 7.32 13 20.95 5.65 6.326 0.02*

Ankle: CF-SM-LF 11 34.14 14.60 13 25.95 9.53 2.262 0.149

Ankle: CF-BC-RF 11 -5.27 13.94 13 -10.45 12.41 0.801 0.382

Ankle: CF-BM-RF 11 27.64 7.83 13 21.20 6.50 4.153 0.056

Ankle: CF-SM-RF 11 34.95 14.90 13 31.65 9.82 0.352 0.560

VM = Valgus motion. CF = Change in flexion. BC = base station to contact. BM = base station to max knee flexion.

SM = contact to max knee flexion. LF = Left foot. RF = Right foot. Variables compared with simple ANOVA.

Levene´s test was used to check if homogeneity of variance was violated. * P<0.05, **P<0,01

Research group Control group

N No injuries

0 1-3 4-7 8-28 28+ 0 1-3 4-7 8-28 28+ 0 1-3 4-7 8-28 28+ Total

Research group 17 4 0 0 0 2 3 0 1 0 5 4 0 0 0 0 2

Total 29 (100%)

Control Group 23 9 0 1 0 1 5 0 0 3 4 4 0 0 0 1 3

Total 37 (100%)

Knee injuries in days lower leg and foot in days Other injuries in days

5 (20%) 10 (30%) 2 (10%)

7 (20%) 11 (30%) 4 (10%)

34

To compare research group to the control group, related to previous

injuries, the frequency of injury were changed slightly. The participants that had

got repeatedly injured in the same body regions were placed in one category

within each group. The category was specified; repeated injury for 28 days or

more. Also, since the sample size was small, the injuries were classified further so

it would be easier to compare the groups. The severity of injury was classified

without regard to their body regions. There was no significant difference between

the groups for previous injuries (p=0.15). This is showen in Table 5

Table 5. The difference in frequency of previus injuries and the players that did not get injuried

Further details of the previous injury are shown in table 6. How many

days the participants were not able to participate in practice or football

competition, what body part was injured and how many repeated injuries were in

every category. This was not especially compared to minutes played in a game or

in practice.

Table 6 Profile of previous injuries and days absent from competition and practice.

Research group 17 4 0 0 0 3 3 7 13

Control Group 23 9 0 0 1 1 3 9 14

N

Total injuried

participants

repeated injury

for 28 days or

more.

28+8-284-71-30No injuries

Variables compared with Chi-spuare test (x2). Levene´s test was used to check if homogeneity of variance was violated.

1.847

injuries in days

sig

0.174

x²(1)

Number of injuries N Days N Days N Days N Days

low back, hip and thigh injuries 12 Knee injuries: 5 lower leg and foot injuries 10 Other injuries: 2

Strain of qutriceps 1 (4- 7) sprain of ligament 1 (8-28) Sprain of ligament 1 (1-3) Broken bones 2 28+

strain of groin 3 (8-28) jumpers knee 1 (8-28) Sprain of ligament 3 (8-28)

strain of Hamstring. 3 (8-28) Sprain of ligament 2 28+ strain of calf 2 (8-28)

Low back injuries 1 28+ Torn meniscus 1 28+ sprain of ligament 3 28+

strain of hamstring 2 28+ of that is Repeated injuries. 1 bone bruise 1 28+

strain of groin 2 28+ of that is Repeated injuries. 4

of that is Repeated injuries. 3

Absent from competition and

practice315+ 140+ 255+ 56+


low back, hip and thigh injuries 15 Knee injuries: 7 lower leg and foot injuries 11 Other injuries: 4

Injuries to the back. 1 0 Contusion to the knee 1 (1-3) shin splint 1 (4-7) Head injuries 1 (8-28)

Contusion to the gluteus 1 (4-7) Sprain of ligaments 1 (8-28) sprain of ligaments 2 (4-7) Dislocation of shoulder 1 28+

strain of groin 4 (8-28) sprain of ligaments 3 28+ Strain of calf 1 (8-28) Broken bone 2 28+

strain of Hamstring. 2 (8-28) torn of meniscus 2 28+ sprain of ligaments 3 (8-28)

Low back injuries 2 28+ of that is Repeated injuries. 2 sprain of ligaments 3 28+

hernia (pain in abdominal) 1 28+ stress fracture of metatarsal 5 1 28+

strain of hamstring 2 28+ of that is Repeated injuries. 2

strain of groin 2 28+

of that is Repeated injuries. 5

Absent from competition and

practice371+ 175+ 245+ 112+

Muscles strain was N = 13 or 45%.

Ligament sprain was N = 10 or 34% other injuries was N = 6 or 21%

Muscles strains was N = 11 or 30%,

ligament sprains was N = 13 or 35%,

other injuries was 13 or 35%

Number of injuries for Research group

Former injuries

Number of injuries for Control group

35

4.2. Injury profile during the football season

In Table 7 the frequency of injuries during the season are shown. In Table

7 are also shown the frequency of injuries for muscles straein, ligament sprain and

the rest of injuries as other for both groups. Total days absent from practice and

competition for each category were also calculated.

Table 7 Profile of injuries during the season and days absent from competition and practice

As shown in table 7, there could by a trend in the total days absent from

competition and training. The control group appears to be more days absent from

competition and training than the research group. But when the frequency of

muscles strain are examined the difference is not that much, research group 3

injuries and the control group 4 injuries. The statistic for injuries during the

football season was also reviewed. The result demonstrated that although the

number of injuries during the season was higher among the control group (n=13)

than the research group (n=5), the difference was not significant between the

groups (P = 0.15) (Table 8).


low back, hip and thigh injuries 3 Knee injuries: lower leg and foot injuries 1 Other injuries: 1

Strain groin 1 (8-28) Sprain ligament 1 0 Head injury 1 28+

Strain groin 1 0

Strain hamstring 1 (1-3)

Absent ftom competition and

practice31 0 0 28+

Mulcels strain was N = 3

Ligament sprain was N = 1

other injuries was N = 1


low back, hip and thigh injuries 5 Knee injuries: 3 lower leg and foot injuries 5 Other injuries:

low-back 1 (1-3) Tear of meniscus 1 28+ sprain of ligament 2 0

strain of Groin 1 (4-7) sprain of ligament 1 28+ contusion of metatarsal bone 1 (8-28)

strain of Groin 1 (8-28) contusion of knee 1 28+ Bone bruise 1 28+

strain of hamstring 2 (8-28) stress fracture meta tarsal 5 1 28+ 0

Absent ftom competition and

practice94 84+ 84+ 0

Muscles strain was N = 4,

Ligament sprain was N = 3,

other injuries was N = 6

Control group

Research group

injurys during season for research group

36

Table 8. Frequency of injuries during season and the number of players that did not get

injured

4.3. Difference in performance parameters before and after the

intervention period.

Table 9 shows the difference in performance test between groups. Max

speed 30 meter, Max jump and max strength/body weight. The difference were

calculated between test M1 and M2 (M2 - M1 = diff)

Table 9. Mean difference in performance parameters before and after the intervention

program

In Max speed test, the research group did lower the mean time for 30

meter sprint (M2 - M1 = diff) compared to control group (F = 5.62, P = 0.02). In

max strength test, the research group improved more (M2 - M1 = diff) than the

control group (F = 4.58, P = 0.04). There was no significant difference in the max

jump test (M2 - M1 = diff) between the groups.

4.4. The result for the kinematic tests for the research group and the

control group before and after the intervention period.

When the difference in kinematic before and after the intervention period

or between test M1 and M2 were calculated the outcome was different. As

outlined in Table 10 there is no significant difference in valgus motion of the knee

before and after the intervention program (M1 – M2). However, there was a trend

in two varibles between the groups VM-BM-LF P = 0.09 and VM-BM-RF P =

0.06, where the control group had slidly higher difference (M2-M1) than the

x²(1) sig

Research group 17 12 2 1 0 1 1 0 5

Control Group 23 10 2 1 1 4 5 0 13

N No injuries 0

injuries in days

2.108

injuries in days

Variables compared with Chi-spuare test (x2). Levene´s test was used to check if homogeneity of variance was violated.

1-3 4-7 8-28 28+

repeated injury

for 28 days or

more.

Total injuried

participants

0.147

N M1 SD N M2 SD diff SD N M1 SD N M2 SD diff SD F Sig.

Max speed. 30 meter (sec) 19 4.193 0.12 19 4.181 0.14 -0.012 0.07 18 4.238 0.14 18 4.296 0.14 0.058 0.11 5.62 0.022*

Max jump (cm) 15 41.145 5.49 15 41.859 5.65 0.73 4.88 15 44.294 5.46 15 40.056 5.43 -3.92 4.88 3.762 0.067

3 rep Max strength/Weight (Ratio) 16 1.54 0.16 16 1.64 0.13 1.056 0.19 16 1.49 0.14 16 1.51 0.12 0.011 0.05 4.582 0.038*


Variables compared with ANOVA. Levene´s test was used to check if homogeneity of variance was violated. * P<0.05. (measurement 1 = M1, measurement 2= M2, difference M1-M2= diff )

37

research group. There was no significant difference in the change in flexion of the

hip (M2 – M1) between the research group and the control group (Table 11).

Table 10. The difference of the mean for the groups in valgus motion in the knee before and

after the intervention periode

Table 11. The difference of the mean in the research and control groups for the flexion in

the hip before and after the intervention periode

There was significant difference between the groups in one variable, Knee:

CF-BC-RF (F = 11:43, P = 0.002). Where research group reduces the flexion

motion of the knee compared to the control group. There was no significant

difference in other measurements for knee flexion motion (Table 12). When the

ankle was examined (Table 13), there were no significant difference of flexion

motion in ankle between the research group and the control group.

M1 SD M2 SD diff SD M1 SD M2 SD diff SD F Sig.

VM-BC-LF 0.95 3.59 1.12 2.29 0.16 3.28 -0.25 3.3 2.45 3.02 2.7 5.02 1.6 0.21

VM-BM-LF -4.2 10.73 0 6.46 4.2 11.8 -3.6 8.92 -1.45 6.81 4.7 7.2 3.2 0.09

VM-SM-LF -4.12 10.08 -1.1 6.2 3.2 11.54 -3.48 8.72 -3.9 4.93 -0.5 7.74 0.87 0.36

VM-BC-RF -0.54 3.42 -1.25 3.44 0.7 5.77 -2.6 4.67 1.05 3.68 3.65 5.96 3.04 0.1

VM-BM-RF -4.8 17.43 6.25 6.66 -1.4 16.68 -12.05 9.15 -1.5 8.51 10.5 11.19 3.87 0.06

VM-SM-RF -4.2 16.32 -5 5.79 -0.7 14.4 -9.65 8.03 -3.95 6.4 5.7 7.34 1.62 0.21

Research group N = 11 Control group N = 13

VM = Valgus motion. BC = base station to contact. BM = base station to max knee flexion. SM = contact to max knee flexion. LF =

Left foot. RF = Right foot. (measurement 1 = M1, measurement 2= M2, difference M1-M2= diff ). If the number in the table has

negative number then there were valgus motion in the knee. Variables compared with Simple ANOVA. Levene´s test was used to

check if homogeneity of variance was violated.


hip: CF-BC-LF 35.3 9.01 31.6 3.96 -3.5 8.94 35.25 9 37.85 8.9 2.6 5.4 3.19 0.09

hip: CF-BM-LF 63.5 10.8 61.54 11.7 -1.77 13.48 60.44 9.6 62.1 8.9 1.6 8.79 0.41 0.52

hip: CF-SM-LF 28.2 10.5 29.9 12.1 1.72 14.33 25.2 7.2 24.25 8.2 -0.95 4.99 0.3 0.59

hip: CF-BC-RF 35.6 8.18 31.7 5.66 -3.5 8.9 35.55 8.8 37.2 8.5 1.65 5.02 2.37 0.14

hip: CF-BM-RF 65.1 14.4 61.9 10.3 -3.18 12.71 60.65 9.5 61.4 7.1 0.75 7.38 0.66 0.42

hip: CF-SM-RF 29.2 14.6 28.1 11.1 -1.27 14.38 26.35 7.9 24.6 6.4 -1.75 5.42 0.009 0.92


CF = Change in flexion. BC = base station to contact. BM = base station to max knee flexion. SM = contact to max knee flexion. LF = Left

foot. RF = Right foot. Variables compared with ANOVA. Levene´s test was used to check if homogeneity of variance was violated.

(measurement 1 = M1, measurement 2= M2, difference M1-M2= diff )

38

Table 12. The difference of the mean for the groups in flexion in the knee before and after

the intervention period

Table 13. The difference of the mean for groups in flexion in the ankle before and after the

intervention period

4.5. The follow-up between the research group and the control group

The tests that were conducted in follow-up measurements throughout the

football season were: The max jump test and 30m sprint. Difference was

calculated between all the measurements (M2, M3, M4). As shown in table 14

there was no significant difference between the groups in the follow-up tests.


Knee: CF-BC-LF 17 7.76 13.0 5.76 -3.95 9.98 11..05 7.55 14.0 5.28 2.95 9.15 3.18 0.09

Knee: CF-BM-LF 61.4 10.22 60.0 11.14 -0.4 5.68 46.6 8.46 51.3 7.53 4.7 6.67 3.20 0.89

Knee: CF-SM-LF 44.4 11.48 47.0 9.62 3.22 5.33 37.8 11.66 37.3 5.65 -0.5 9.32 0.84 0.36

Knee: CF-BC-RF 16.09 6.09 11.08 4.48 -4.95 7.4 7.95 5.34 16.0 4.45 8.05 8.17 13.63 0.002**

Knee: CF-BM-RF 48 10.85 60.08 8.28 11.5 9.25 53.0 7.39 57.3 6.77 4.3 8.14 3.09 0.094

Knee: CF-SM-RF 47.54 10.36 48.36 9.11 0.81 -0.81 45.05 6.7 41.3 6.84 3.75 5.08 2.1 0.16


CF = Change in flexion. BC = base station to contact. BM = base station to max knee flexion. SM = contact to max knee flexion. LF = Left foot. RF = Right foot.

(measurement 1 = M1, measurement 2= M2, difference M1-M2= diff ). Variables compared with ANOVA. Levene´s test was used to check if homogeneity of

variance was violated. **P<0,01


Ankle: CF-BC-LF -5.95 16.5 -4.6 16.4 1.13 13.7 -0.95 19.1 -7.3 13 6.35 19.3 0.84 0.37

Ankle: CF-BM-LF 26.7 7.31 26.7 4.65 1 5.22 20.95 5.73 21.95 7.6 1 8.42 0.33 0.57

Ankle: CF-SM-LF 34.13 14.6 31.37 15.2 2.13 13.4 25.95 10.3 29.25 9.6 3 7.57 1.16 0.29

Ankle: CF-BC-RF -5.27 13.9 -3.55 23.9 -1.72 13.9 -10.45 14.3 -9.8 14 0.65 9.32 0.02 0.88

Ankle: CF-BM-RF 27.63 7.82 29.6 11.6 -2 12.9 21.2 6.51 23.4 5.9 -1.6 6.67 0.002 0.96

Ankle: CF-SM-RF 34.95 14.9 31.54 15.2 1.8 9.04 31.65 13.2 33.2 13 -1.1 5.41 0.92 0.34


CF = Change in flexion. BC = base station to contact. BM = base station to max knee flexion. SM = contact to max knee flexion. LF =

Left foot. RF = Right foot. (measurement 1 = M1, measurement 2= M2, difference M1-M2= diff ). Variables compared with ANOVA.

Levene´s test was used to check if homogeneity of variance was violated.

39

Table 14. Mean difference in performance parameters in the follow-up.

4.6. The chances in performance between measurements in tests M1

through M4 with in the groups.

In the research group, there was a significant difference between the tests.

Max speed. 30 meter (F = 1.17, P = 0.03), Max jump (F = 5.51, P = 0.01) and

Max strength/body weight (F = 5.82, P = 0.03), (Table 15). There were

improvements in all test results from M1 to M2 or M3, but not between M3 and

M4 (speed and jump tests). On the other hand, no such difference was found in

the control group, where the control group did not improve its performance

significantly between measurements of tests M1 to M4.

Table 15. The mean difference in performance parameters within groups in the follow-up


Max speed. 30 meter (sec) 6 4.12 0.14 6 4.06 0.8 -0.6 0.12 10 4.31 0.08 10 4.22 0.16 -0.09 0.12 0.461 0.5

Max jump (cm) 6 43,05 6.69 6 46.36 5.31 3.46 3.56 10 40.33 3.72 10 42.55 5.59 2.21 3.2 0.35 0.55


Max jump (cm) 11 43,15 6.69 11 46.2 6.8 2.99 3.04 10 40.33 3.72 10 40.167 5.14 -0.17 3.67 2.56 0.11


Max jump (cm) 6 46.2 6.8 6 46.36 5.31 1.8 9.02 10 40.167 5.14 10 42.55 5.59 2.38 2.89 1.6 0.57

(measurement 2 = M2,measurement 3= M3, measurement 4= M4, difference M2-M3)= diff) difference M2-M4= diff ). Variables compared with ANOVA. Levene´s test was used to check

if homogeneity of variance was violated.


N M1 SD M2 SD M3 SD M4 SD F Sig.

Max speed. 30 meter (sec) 6 4.15 0.12 4.13 0.14 N/A N/A 4.05 0.08 4.33 0.027*

Max jump (cm) 6 41.84 8.14 42.88 7.47 46.54 7.55 46.36 5.31 5.51 0.013*

3X Max strength/Weight (ratio) 16 1.54 0.16 1.64 0.13 N/A N/A N/A N/A 5.82 0.026*

M1 SD M2 SD M3 SD M4 SD F Sig.

Max speed. 30 meter (sec) 10 4.24 0.12 4.31 0.08 N/A N/A 4.22 0.16 2.55 0.11

Max jump (cm) 10 42.5 5.64 40.33 3.7 40.16 5.14 42.55 5.59 1.55 0.2

3X Max strength/Weight (ratio) 16 1.49 0.14 1.51 0.12 N/A N/A N/A N/A 8.21 0.3

(measurement M1,M2,M3,M4). ANOVA repeated Measures. The Sphericity Assumed test was used to identify whether

there was variability in the tests. *P<0,01

Research group

Control group

40

5. Discussion

In this study the main aim was to: investigate the effect of a specially

designed intervention program for football, to test if there were a difference in

performance, reduction of risk factors in knee and reduction of injuries in football

season 2013. Also to compare these factors between the research group which

followed the program and the control group. A special strength training program

was designed for the research group that was followed up by the researcher. For

the control group the coach designed a basic strength training program, in which

the kettle bells were used. The intervention period lasted for five training weeks

and the follow-up program lasted throughout the football season.

The main result in this study were that there was no significant difference

between the groups related to injuries. The specialised strength training program

appears to be beneficial for the research group related to strength (p = 0.04) and

speed (p = 0.02). But for power (max jup test) there was no significant difference

between the groups. In the kinematic measurments; there was no significant

difference between the groups exept for one variable. In the follow-up there was

no significant difference between the groups.

5.1. Comparison for injuries:

When the two groups were examined related to injuries in the 2013 season.

All injuries were taken in consideration, both contact and noncontact. There was

no significant difference between groups; the population was small so lack of

power could be one reason why significant difference was not found. It would

have been better if the registration of injuries i.e. the frequency of injuries had

been calculated per 1000 player hours in games and practice like some other

studies have done (Árnason, et. al., 2004; Árnason, 2008). It would have been

easier to compare the groups and it would have been more reliable result in the

study. The specialized strength training program that was made for the research

group, with emphasize of exercises was strength, dynamic stabilization factor and

power training did not seem to have prevention factors for injuries, no significant

difference was detected between the groups. Different result have been shown

from other studies were prevention programs should emphasize on strengthening

hamstring and the activation of the hamstring muscle (Ford et. al., 2005; Hewett

et. al., 2012; Hewett et. al., 2008; Ahmad et. al., 2006; Munro et. al., 2012;

41

Petersen & Holmich, 2005; Opar et. al., 2012; Árnason, 2009; Arnason et. al.,

2008). Neuromuscular training could also lead to reduction of ACL injuries and a

hamstring injury by increasing neuromuscular control that perhaps improves the

biomechanical function of the knee. The neuromuscular adaption optimizes the

reaction time that would provide greater pre-contraction of the muscles (Ford et.

al., 2005; Hewett et. al., 2012; Hewett et. al., 2008; Ahmad et. al., 2006; Munro

et. al., 2012). Also the neuromuscular training is effective for many parts of the

body, especially for lumbo-pelvic complex, hamstring and other muscles of the

lower extremities and generally increases fitness level and control which in return

reduces injuries (Se & Kp, 1998; Kornberg & Lew, 1989; Cibulka et. al., 1986;

Hennessey & Watson, 1993; Opar et. al., 2012). Specific type of exercises has

been proven effective for prevention of hamstring injuries. These exercises

emphasize strengthening of hamstring in an eccentric contraction, like Nordic

hamstring lowering exercise (Petersen & Holmich, 2005; Opar et. al., 2012;

Árnason, 2009; Arnason et. al., 2008). On the other hand, emphasize on eccentric

strength was not considered in this study. But that could be an interesting training

factor in the specialized strength training program. Other training factors have

been shown to contribute to preventing injuries; like physical conditioning, which

correlates to fatigue in muscle. It is believed that reduced capacity of lengthening

in muscles makes it more likely to sustain strain injuries (Petersen & Holmich,

2005; Opar et. al., 2012). In the following studies of risk factors like flexibility,

muscle strength imbalance, anatomical alignment, playing surface and equipment

(Meeuwisse et. al., 2007; Meeuwisse, 1994; Bahr & Holme, 2003) and Vo2 max

levels were not measured, but those risk factors could be important to explain part

of injuries in football. Sports related injuries are in fact multifactorial (Meeuwisse,

1994; Meeuwisse et. al., 2007). From that point of view the conditioning program

for football should cover all aspect of physical training, the strength, power,

speed, dynamic balance, neuromuscular training, stabilization and more. But

there is need for further research in this field.

When looking at severity of the injuries during the football season in Table

8, the most frequent severity was severe (33%) and moderate injuries (28%), but

the fewest were minor (22%), minimal (11%) and mild (6%). In other studies the

severe injuries only count for 10% of the injuries, moderate 25% and the most

frequent are classified as mild or minor or 65% (Rahnama et. al., 2002; Wong &

42

Hong, 2005; Engstroem et. al., 1991; Hägglund et. al., 2009; Lüthje et. al., 1996;

Hawkins & Fuller, 1999; Hawkins & Fuller, 1998; Árnason, 2004; Hawkins et.

al., 2001). One of the reasons that this is different in this study could be the

method of injury registration. The registration was self-reported from the

participants after the season 2013 and maybe they don’t consider minor as an

injury or just forget minor to mild injruies.

Previous injuries in the research group were muscle strains (N = 13 or

45%), ligament sprains (N = 10 or 34%) and other injuries (N = 6 or 21%). In the

control group the most common injuries were muscles strains (N = 11 or 30%),

ligament sprains (N = 13 or 35%) and other injuries (N = 13 or 35%) (Table 6).

According to this the assumption is made that there is not much difference

between the groups in physical conditioning, in that case it probably had not much

effect on the study. The most common injury types in the research group during

the season 2013 was muscle strains (N = 3), ligament sprains (N = 1) and other

injuries (N = 1). For the control group the main injury types were muscles strain

(N = 4), ligament sprains (N = 3), other injuries (N = 6). This is similar to other

study were muscles strain and ligament sprains are most frequent (Árnason, 2004;

Árnason, 2008) (Table 7). In table 6 former injuries and in table 7 injuries during

season is demonstrated, as well as the frequency and the severity of injuries in

days absent from competition and practice. It can be argued that there is not much

difference between groups in muscle injuries considering the frequency. The

result of this study demonstrated that there was no significant difference in

injuries between the groups (P = 0.15). Although the number of injuries during the

season was higher among the control group (n=13) than the research group (n=5)

(table 8). But this needs further research. Another factor that has not been

mentioned before is that the research group had to play more football games

because of European championship wich was not seen before the study start, this

could also be factor related to injuries during season 2013 and make the two

groups not homogeneous.

5.2. Comparison related to kinematics

When the difference for kinematic parameters as valgus motion in knee, flexion

motion for hip, knee and ankle were calculated (M2 – M1) with in the groups,

then difference between the research group and the control group was sparse. The

43

result demonstrates; only one variable that had significant difference after the

intervention program. Where research group reduces the knee flexion on right

foot, from base station to initial contact. But there was no significant difference

between the groups, in all the other variables in the kinematic measurement, for

the hip, knee and ankle. This is in contrast to one of the hypothesis in the

research: The research group is going to have better movement kinematic on a

forward jump landing task in lower extremities; that is greater flexion angle

movement in hips, knee and ankle, from the lateral view, compared to the control

group. Where it was argued, that specialized strength and power program could

have better result in kinematics for the research group in forward lunge jump test.

Other studies and articles have demonstrated that different types of training like

dynamic stabilization and plyometric training can make difference in movement

in lower extremities:

Valgus motion of the knee: Studies are found that indicate that

plyometric and dynamic balance training can lead to reduced valgus in the knee

(Chimera et. al., 2004; Shultz et. al., 2010; Myer et. al., 2005; Mandelbaum et. al.,

2005; Petersen et. al., 2005; Myer et. al., 2006). Most of those publications are

related to valgus motion in knee for women because women are more in risk of

getting ACL injuries and valgus motion is one of the risk factors (Waldén et. al.,

2011; Ford et. al., 2005; Hewett et. al., 2012; Hewett et. al., 2008; Ahmad et. al.,

2006; Koga et. al., 2010; Krosshaug et. al., 2007; Chappell et. al., 2002; Munro et.

al., 2012). Consequently the result of this study is probably not correlated to

increased valgus motion in men.

Flexion motion of the hip: One study shows difference between basic

strength training program and plyometric and dynamic balance program, were the

plyometric and dynamic program is believed to provide better coordination of

hamstring muscles activation which may increase stability of knee and hip

(Lephart et. al., 2005). There is evidence that support that increased flexion in hip

is related to ACL injuries for women (Hewett et. al., 2005). When looking at the

literature there is not much data relating increased hip flexion in a jump and

landing task to injuries in men. Which could be one of the reasons that there was

no difference between the groups. In this study the strength program for both

groups could have similar effect on flexion in hip? Or perhaps the flexion in hip is

44

not a factor for injuries in lower extremities for men? This needs to be further

studied.

Flexion motion in the knee: Like said before there was a significant

difference in one variable after the intervention period, between the research

group and the control group. Where research group reduces knee flexion; on right

foot, from base station to initial contact in landing after the forward lunge jump.

There was no significant difference in other variables. Other studies argued that

plyometric and dynamic balance training increases flexion and this type of

training is considered important to knee stabilization in sport that has great knee

angles (Myer et.al., 2006; Myer et.al., 2005; Mandelbaum et.al., 2005; Petersen

et.al., 2005). It has also been argued that increased knee flexion can give the

hamstring a better torque and then a better support for the ACL (Huston &

Wojtys, 1996; Hirokawa et.al., 1991). It has also been demonstrated that both

basic strength and plyometric training increased knee flexion in touch with the

ground, and the maximum flexion in the landing (Lephart et.al., 2005; Huston &

Wojtys, 1996).

Flexion motion in the ankle: In this study the change of dorsal flexion

in landing task after forward lunge jump was examined. This was different from

other study. They examined the movement of the ankle in coronal plain in

jumping and landing. It has been argued that increased motion in ankle in coronal

plain could be related to increased risk of ACL injuries in women (Ford et. al.,

2005). The mechanical stability of the ankle has also been examined as predictor

to injuries (Arnason et. al., 2004). In the present study mechanical stability and

motion in coronal plain was not examined. This could be the reason that there was

no difference between the groups and the strength training programs for both

groups are contributing equally to flexion motion in ankle.

According to the results there is not possible to predict whether the

research group had better performance or the control group. In only one of 24

measured kinematic variables was significant difference in favor of the control

group, were the difference in kinematics was calculated between M1 and M2.

This one variable that had significant difference between the groups could only be

by chance, we don’t know. There is need to have more participants to have more

statistical power to be able to predict in these kind of study. So our hypothesis is

rejected. In this context it might be important to find other ways to measure risk

45

factors in lower extremities for men. It is mentioned above that injuries in

football are multifactorial and many factors needs to be taken in the model when

measuring the difference between factor before and after intervention program.

5.3. Comparison in Measurements of the Performance tests:

When the performance parameters in 30 meter speed test and 3 rep-max

strength tests are viewed, related to performance, the result demonstrated

significant difference between the two groups. The research group did improve

their speed (p = 0.2) and strength (P = 0.04) in test M2 compared to test M1, after

the intervention period. But the control group had less average speed in the second

speed test M2 compare to test M1. The same was in 3 rep-max strength test were

the research group did perform better than control group, after the intervention

period.(p = 0.04) This is in consistence with one of the research hypothesis: The

research group will have equal or better speed, power and strength performance

after the intervention program, in mid-season and after the football season,

compared to the control group. In the light of this the research hypothesis is

approved. This is in accordance to other studies (Helgerud et. al., 2003; Wilson

et. al., 1993; Fatouros et. al., 2000; Rimmer & Sleivert, 2000). In has been argued

that plyometric training increases power both with and without resistant training,

both in sprinting speed and jumping height (Wilson et. al., 1993; Fatouros et. al.,

2000; Rimmer & Sleivert, 2000). Many researchers have recommended the

combination of plyometric and strength training rather than either plyometric or

strength training alone (Adams et. al., 1992; Fatouros et. al., 2000; Harris et. al.,

2000; Toji et. al., 1997). Like in the study from Lytte et al. (1996), were combined

training group did perform better in dynamic sports other than strength training

alone (Lyttle et. al., 1996). Similar results have been seen from other researchers

(Harris et. al., 2000; Barber-Westin et. al., 2010). On the other hand the result

from max-jump test in the present study reveals that there was no significant

difference between the groups in test M2 compared to M1. In that case the

research question was rejected. This result is in accordance with other study that

it was argued that it was not necessary to exercise plyometric training when the

football team is practicing football at the same time (Ronnestad et. al., 2008).

Based on these results there is possibility that the specialized strength

training program could be beneficial to football players related to strength and

46

speed on the other hand not for power. But there are other factors that were not

taken in consideration in this study; the different coaching style, conditions for

practicing football, equipment for training, practice time and total frequency all

training sessions both football and physical conditioning, as well as total training

load.

5.4. Comparison in follow-up measurements:

In the follow-up measurements of test M3 and M4 for power and speed,

the statistical analyses reveal that there was no significant difference between the

groups. In light of that the research hypothesis was rejected. The population was

small in M4, both for the research group (N = 6) and for the control group (N =

10). That indicates low statistical power and could be the reason for no significant

difference between the groups in the follow-up tests.

When the difference in performance tests M1, M2, M3 and M4 was

calculated within the groups, there was significant difference in the research group

between the following tests: 30 meter speed test M1 to M4, Maximum strength

test M1 to M2 and max jump test M1, M2, M3 and M4. On the other hand there

was no significant difference between the performance tests for the control group.

In the light of result, the research hypothesis: The performance in speed, power

and strength will increase during the intervention period, the performance will be

the same or increase in the follow-up throughout the football season 2013, with in

the research group and the control group, is accepted for the research group but

rejected for the control group. On the other hand the sample was small as said

before, so it is not possible to say with great reliability that these results is

reflection for the whole football team, or if the data would support the research

question or not. Hypothetically if the data reflect the whole team, then as said

before these findings are similar to other studies, that combination of strength,

plyometric and dynamic strength training can give a better performance than

doing strength training alone (Adams et.al., 1992; Fatouros et.al., 2000; Harris

et.al., 2000; Toji et.al., 1997; Lyttle et.al., 1996; Barber-Westin et.al., 2010). But

this is only hypothetically and further research is needed were the number of

participants is more.

47

5.5. Disadvantages and Defects

In the follow-up the participants did not attend to the measurement and

there were flaws in measurement M4. Because there were only six that attended

for the research group similar was for the control group. The injuries registration

could have been better, in the way of taken down the injuries weekly or monthly

during the football season, in better partnership with participants, coach and the

physiotherapist of the team. Also it would have been better if incidence had been

calculated, frequency of injuries per 1000 player hour in games and practice

(injuries/1000hour). It would have been easier to compare the groups to gather

and it would have been more reliable result in the study. In the kinematic

measurements, other risk factors could have been examined, that can reflect

injuries mechanism better for the male football player. The power of the results

would have been bigger if more football teams had participated in the study.

It should be considered that other training factors could have influenced

the results of this study, like different coaching style, conditions for playing

football, equipment for training, practice time, lifestyle and frequency of training

sessions both football, and physical conditioning.

5.6. Benefits

The Benefits from the research may include: If efficacy of the special

program works well then coaches can use it immediately. That is for the football

player’s benefits. Further more, if the hypothesis would be tested on a bigger

cohort and is proven to be significant, then this type of a program or other with

similar design can be beneficial both to the coach and the football player related to

performance and reducing the chance of injuries.

6. Conclusion

It is important to find a strength training program that is beneficial for the

football players to make them perform better in football. Lowering the injury risk

of the football players is one of the most important thing. If the player is injured

he can’t take part in football practice or games. It can also be expensive both for

the football players and the football teams. In this study it was hypothesized that

special strength training program that has emphasis on a dynamic balance factor

in every strength and power exercise would be able to reduced injuries for the

48

research group but also have same or better increase in strength, power and sprint

speed as the control group.

The conclusion is below in categories:

Injuries: There was no significant difference in injuries between the research

group and control group during the football season 2013.

Performance in sprint speed, strength and power: There was significant

difference in strength and sprint speed between groups. But the difference in

power was not significant between groups.

Kinematics: There was no significant difference between the groups related to the

difference between the measurements M1 and M2.

It seems the specialized strength training program was beneficial for the

research group, related to speed and strength compared to the strength training

program for the control group. But for injuries, power and kinematic

measurements, no significant difference were found between the groups.

For future researches it is recommended to find different kinematic

measurement to try to explain possible difference in frequency of injuries related

to different types of strength training programs. To be able to predict injuries

better and to see what risk factors are changing related to kinematics, when

different types of strength training programs are executed for football. There is

also a need to have more participants involved in the studies to get better

statistical power.

49

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65

7.1. Appendix. Upplýst samþykki

Upplýst samþykki

Fyrirbygging meiðsla með styrktarþjálfun og

vöðvastjórnun

Markmið rannsóknarinnar er að bera saman tvær mismunandi

þjálfunaraðferðir, þar sem annarsvegar er notast við hefðbundna styrktarþjálfun og

hinsvegar sérhæfða styrktarþjálfun. Með þessu er verið að skoða hvort sérhæfð

styrktarþjálfun gefi sambærilegan árangur í styrk og kraft miðað við hefðbundna

styrktarþjálfun og að auki hafi hún þann kost að vera fyrirbyggjandi fyrir meiðsli í

íþróttum.

Þátttaka í rannsókninni felur í sér að þátttakandi þarf að gefa upplýsingar um sögu

meiðsla og mæta í mælingu. Auk þess er nauðsynlegt að skrá meiðsli sem

þátttakandi verður fyrir þar til að rannsóknartímabili er lokið. Mælingar sem

framkvæmdar eru eru skipt í 4 meginþætti; 1. Mælingar fyrir inngrip

(styrktarþjálfun), 2. Inngrip (styrktarþjálfun), 3. Mælingar eftir inngrip

(styrktarþjálfun) og 4. Eftirfylgni, mælingar um sumar og eftir tímabil í fótbolta.

Einnig fær rannsóknarhópur þjálfunarprógram út tímabilið. Þáttur 1 og 3.

Til að mæla styrk er notast við hnébeygju (mælieining kílógrömm). Hraða, 30

metra sprettur, mælieining sekúndur. Til að mæla kraft er notað jafnfætishopp og

hæð mæld i sentimetrum. Gerð verður hreyfigreining með háhraða

myndbandsupptöku. Mælingar munu fara fram í húsakynnum íþróttafélaga í

Reykjavík. Þáttur 2 er æfingarprógram sem er sett upp fyrir þátttakendur í 5

vikur. Hver mæling tekur u.þ.b. klukkustund sem er framkvæmd fyrir og eftir

inngrip, en inngrip tekur 5 vikur. Mælingar og þjálfun fer fram í húsakynnum

Háskólans og í húsakynnum íþróttafélags.

Ég staðfesti hér með undirskrift minni að ég hef lesið upplýsingarnar um

rannsóknina sem mér voru afhentar, hef fengið tækifæri til að spyrja spurninga um

rannsóknina og fengið fullnægjandi svör og útskýringar á atriðum sem mér voru

óljós. Ég hef af fúsum og frjálsum vilja ákveðið að taka þátt í rannsókninni. Mér

er ljóst, að þó ég hafi skrifað undir þessa samstarfsyfirlýsingu, get ég stöðvað

66

þátttöku mína hvenær sem er án útskýringa og án áhrifa á þá læknisþjónustu sem

ég á rétt á í framtíðinni. Mér er ljóst að rannsóknargögnum verður eytt að

rannsókn lokinni og eigi síðar en eftir 5 ár frá úrvinnslu rannsóknargagna. Mér

hefur verið skýrt frá fyrirkomulagi trygginga fyrir þátttakendur í rannsókninni.

_______________ _______________________________

Dagsetning Undirskrift þátttakanda

Undirritaður, starfsmaður rannsóknarinnar, staðfestir hér með að hafa veitt

upplýsingar um eðli og tilgang rannsóknarinnar, í samræmi við lög og reglur

um vísindarannsóknir.

________________________

Jóhannes Már Marteinsson nemi

við Háskólann í Reykjavík

67

7.2. Appendix. Kynningarbréf til væntanlegra þátttakenda

Fyrirbygging meiðsla með styrktar þjálfun og vöðva stjórnun

Ábyrgðarmaður rannsóknar: Nafn

Einar Einarsson Starfsheiti

Aðjúnkt við

Háskólann í

Reykjavík

Sími

840-7806 Netfang

[email protected]

Aðrir sem koma að rannsókninni:

Nafn

Baldur Þorgilsson Starfsheiti

Aðjúnkt við

Háskólann í

Reykjavík

Sími

840-7802 Netfang

[email protected]

Nafn

Pétur Sigurðsson Starfsheiti

Lektor við Háskólann

í Reykjavík

Sími

599-6343 Netfang

[email protected]

Nafn

Jóhannes Már

Marteinsson

Starfsheiti

Meistaranemi við

Háskólann í

Reykjavík

Sími

660-1206 Netfang

[email protected]

Kæri íþróttamaður,

Fyrirhugað er að hefja ofangreinda rannsókn á vegum Tækni- og

verkfræðideildar Háskólans í Reykjavík sem námsverkefni til meistaragráðu í

íþróttavísindum og þjálfun.

Markmið rannsóknarinnar er að bera saman tvær mismunandi

þjálfunnaraðferðir, þar sem annarsvegar er notast við hefðbundnar styrktar þjálfun

og hinsvegar sérhæfða styrktarþjalfun. með þessu er verið að skoða hvort

sérhæfð styrktarþjalfun gefi sambærilegan árangur í styrk og kraft og hefðbundin

styrktarþjalfun og að auki hafi hún þann kost að vera fyrir byggjandi fyrir meisli í

íþróttum.

Fyrirhugað er að skoða 52-84 knattspyrnumenn og konur sem taka þátt í efstu

deild á Íslandi, 18 ára og eldri. Fyrir hugað er að skoða áhrif sérhæfðar

styrktarþjálfunnar fyrir íþrótta menn með það í huga að hafa fyrir byggjandi þætti

tvinnaða inn í styrktarþjálfunnina þannig að hún get minkað líkur á meiðslum og

aukið styrk. þetta svo borið saman við hafðbundna styrktarþjálfun. Þetta er svo

68

skoðað hvort þessar mismunandi þjálfunnar að ferðir gefir ekki sambærilegan

styrk en sérhæfðstyrktaþjalfun sé einnig fyrir bygjandi fyrir meiðsli.

Til þess að taka þátt í rannsókninni þurfa væntanlegir íþróttamenn að

undirrita upplýst samþykki um að þeir hafi lesið kynningablað um

rannsóknina og geri sér grein fyrir hvað felst með þátttöku í rannsókninni.

Rannsóknin felur í sér fjorar mælingar og þjálfunnar áætlum í 6 til 8 vikur. sem

munu fara fram á íþróttasvæði íþróttafélags eða í húsakynnum Háskólans í

Reykjavík. Um er að ræða tvær mælingar sem taka að hámarki eina klukkustund.

Nauðsynlegt er að íþróttamenn séu léttklæddir á meðan á mælingum stendur, það

er að segja í hjólabuxum/sundfatnaði og berir að ofan og kvenkyns íþróttamenn

auk þess í íþróttatopp. Á milli þessa mælinga er gert inngrip. inngripið felst í

þjálfunnar áætlun sem tekur 5 vikur. Auk mælingar munu íþróttamenn gefa

upplýsingar um hæð, þyngd, ríkjandi fót, stöðu á velli og nákvæmar upplýsingar

um fyrri meiðsli.

Áætlað er að framkvæma eftirfarandi mælingar sem eru gerðar fyrir og eftir

ingrip(þjálfurn)

syrktarmæling. Hnébeigja 3 Rep, max

snerpa. 30 metra sprettu úr kirrstöðu að 30m. mældur með fotosellu.

Kraftur. mældur með hopp prófi. lóðréttu hoppi úr kyrrstöðu.

Hreyfigeyning gerð til að meta likur á meiðslum.

Hopp með lendingu á öðrum fæti tekið upp á háhraða videovélar

Ingrip felur í sér þjálfunnaráætlun sem felur í sér að annar hópur sem er

rannsóknar hópur fær ser hannað styrktar prógram. þar sem flestum hafðundnum

lyftingar æfingaum er breyt þannig að þær valda meira álagi á vöðvastjórnun og

stöðuleika þáttum vöðva og liðamóta. en hinn hópurinn sem er viðmiðunnarhópur

fær hefðbundið styrktarprógram.

Að loknum mælingum skrá íþróttamenn niður meiðsli (ef þau eru til staðar) á

rannsóknartímabilinu, þ.e.a.s þangað til að síðari mæling hefur verið framkvæmd.

Áhætta af þátttöku í rannsókninni er lítil þar sem að þær hreyfingar sem

íþróttamenn munu framkvæma eru einfaldar í útfærslu. Það er því óveruleg

69

hætta á meiðslum þegar mælingar eru framkvæmdar, í ingripi er einnig litlar líkur

á meiðslum. þar sem hreyfingar eru likar þeim hreyfingum og æfingum sem er

verið að framkvæma í leik. En ómögulegt er að útiloka að slíkt geti komið fyrir.

Íþróttamenn eru, ef við á, tryggðir hjá Sjóvá á meðan mælingar og ingrip stendur

yfir.

Þær upplýsingar sem íþróttamenn veita í rannsókninni verða meðhöndlaðar

samkvæmt reglum um trúnað og nafnleynd og farið að íslenskum lögum

varðandi persónuvernd, vinnslu og eyðingu frumgagna. Spurningarlistar og

niðurstöður úr mælingum verða merkt með númerum en ekki nöfnum

þátttakenda. Geymsla á gögnum verða í tölvum læstum með notendanafni og

lykilorði og/eða læstum hirslum eftir því sem við á. Eftir úrvinnslu og eigi

síðar en fimm árum eftir að rannsókn lýkur verður öllum gögnum eytt. Nöfn

eða aðrar persónugreinanlegar upplýsingar koma því hvergi fram við

úrvinnslu gagna eða birtingu niðurstaðna.

Niðurstöður rannsóknarinnar verða nýttar til meistaragráðu í íþróttavísindum

og þjálfun við Háskólann í Reykjavík. Auk þess er sá möguleiki fyrir hendi að

vísindagrein byggð á gögnunum verði birt í vísindatímariti.

Þátttakandi getur hafnað þátttöku eða hætt í rannsókninni á hvaða stigi sem

er án útskýringa.

Þessi rannsókn hefur hlotið leyfi Vísindasiðanefndar og verið tilkynnt til

Persónuverndar.

Virðingarfyllst,

____________________________

Einar Einarsson, aðjúnkt

Ábyrgðarmaður rannsóknar

____________________________

Pétur Sigurðsson, lektor

____________________________


"Ef þú hefur spurningar um rétt þinn sem þátttakandi í vísindarannsókn eða vilt hætta þátttöku í

rannsókninni getur þú snúið þér til Vísindasiðanefndar, Hafnarhúsinu, Tryggvagötu 17, 101

Reykjavík. Sími: 551-7100, fax: 551-1444, tölvupóstfang: [email protected]."

mailto:[email protected]

70

7.3. Appendix. Samstarfsyfirlýsing

Samstarfsyfirlýsing

Jóhannes M. Marteinsson mastersnemi í íþróttafræði við Háskólann í Reykjavík

hefur letað eftir samstarfi við íþrótta félagið__________________ vegna

rannsóknar á fótbolta mönnum. Þar sem íþróttafélagið aðstóðar við ransóknina

með því að útvega þáttakendur í hana.

Þátttaka í rannsókninni felur í sér að þátttakandi þarf að gefa

upplýsingar um sögu fyrri meiðsla og mæta í mælingu. Auk þess er nauðsynlegt

að skrá meiðsli sem þátttakandi verður fyrir þar til að rannsóknartímabili er lokið.

Mælingar sem framkvæmdar verða er skipt upp í þrjá meginþætti. 1) Mælingar

fyrir inngrip (styrktarþjálfun). 2) Inngrip (styrktarþjálfun). 3) Mælingar eftir

inngrip (styrktarþjálfun). Í þætti eitt og þrjú, til að mæla styrk, er notast við

hnébeygju (mælieining kílógrömm (kg)). Til að mæla hraða verður 30 metra

sprettur (mælieining sekúndur (s)). Til að mæla kraft er notað jafnfætis hopp og

stökkhæð mæld (mælineining sentimetrar (cm)). Gerð verður hreyfigreining með

háhraða myndbandsupptöku. Mælingar munu fara fram í húsakynnum

íþróttafélaga og í Háskólanum í Reykjavík. Í þætti tvö er 5 vikna

styrktaræfingaprógram sett fyrir þáttakendur. Hver mæling, sem er framkvæmd

fyrir og eftir inngrip, tekur u.þ.b. klukkustund.

Íþróttafélagið staðfestir með undirskrift sinni að þeir hafi kynnt sér

upplýsingar um rannsóknina og haft tækifæri á að spurja spurninga um

rannsóknina. Íþróttafélaginu er einnig ljóst að þeir meigi draga sig úr þáttöku

rannsóknar hvenær sem er án nokkurrar útskýringar.

Undirskrift ábyrðarmans

______________________kt.______________

Undirskrift rannsakanda

______________________kt_______________

Undirskrift fyrir hönd íþróttafélags

______________________kt_____________

71

7.4. Appendix. Annual plan and pictures of exercises In this section there is the overview for the specific strength program from the start of the study week 8 thru the end week 40. Also

pictures of exercises that were done in practice 1 and 3 per week not all of the exercises that are in the pictures are don in every practice. The

second practice that were done per week is also shown in pictures that was a field practice done with medicine balls, hurdles, footballs and own

body weight.

Annual plan

Key words. VH= wery high, H= high, M= medium, L= low, VL= wery low, SPW= session per we

okt

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

co

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PerformanceintensityVolume

Geniral preparation GPP specific preparation SPP / Precompetition main copitition

oktdes jan apr

Annual plan for. Strength training for footballMonth nov julfeb mars mai jun agust sept

loads g

raf

Trainingg w eek

Periods/phases

priority/Levell

72

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39

Strenght x x x x

Pawer x x x x

speed x x x x

Performance

VH x x x x x x x x x xH x x x x x x x x x x x x x xM x x x x x x xL xVL

VH xH x x x x xM x x x x x x x x x x x x xL x x x x x x x x x x x x xVL

Strength endurance. SPW

Maximum strength. SPW

Strength-speed SPW 2 2 1 1Speed-strength SPW 1 1 2 2 3 3 3 2 2 2 2 2 2 2 2 2 1 1 1 1 2 2 2 1 2 1 2 1 2 1 2 1Speed. SPW 1 1 1 1 1 1 1 1 1 2 2 2 2 1 1 1 2 1 2 1 2 1 2 1 2

9864 5 7

Indicative load

Testing.

Weekly

in

tensity

Weekly

volu

me

Stength and pow

er

Mesocycles 2 3

Microcycles

1

73

Endurance SPW 2 2 2 2 2 2 2 1 1 1 1 1 1 1Speed endurance SPW 1 1 1 1 1 1 1 1 1 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1top speed SPW 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1ecceliration SPW 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

focus in training

Phycologycal skils

flexibility training IETS

Runnin

g

emphasis

Visualisation coping with volume

Strength endurance and maximum strength. Stability and

Dynamic balance. Exercises are sprt-like, that applies to

the strength training. At the end of this period, there are

more Strenght speed exercises. ólympic weighth lifting

become more bart of the training and plyometric exercises.

Visualisation, coping with stress prepering for competition Visualisation, coping with stress and competition

maintaining maximum strength and

move Strength training more in to

power training, where more and more

thought about speed and Explosive

Power. exercises are implemented so

that they are sport like and contribute

to improving the dynamic balance and

the result can reduce the probability of

injury

maintain maximum strength and bring more strength into power training where

more and more thought about speed and Explosive Power. exercises are

implemented so that they are sport like and contribute to improving the

dynamic balance and can probably reduce the risk of injury

Reduced focus on

strength while still

maintaining strength. It is

mainly done by

increasing power idea in

exercises. fewer reps and

medium heavy weights

weightlyfts , but more

speed and explosive

power. Emphasis is

placed on the sport like

exercises and stability,

dynamic balance,

strengthen the Athlete

better to respond to

spontaneous movements

such as agility and other

similar exercises

maintaining maximum

strength and transferred

into power with exercises

that build on strength and

speed and Speed

Strenght. These exercises

will also focused on

dynamic balance. Which

should reduce the

probability of injury. And

strength the Athlete to



as agility and other similar

movement

Maintaining

maximum

strength and main

emphasis is on

speed strength

and speed. Also

a strong focus on

training that are

sport like training

and have stability

factor in the

exercises and

dynamic balance

Consequently,

preventive

exercises for

injuries

Reduced focus on

strength while still

maintaining strength, it is

mainly done by

increasing power in

thought in exercises.

Smaller weights in weight

lyfts tion but more speed

and explosive power.

Emphasis is placed on the

sport like exercise and

stability, balancing and

strengthen the Athlete



such as agility and other

similar exercises.

74

overview for the intervention program for the research group

week Training emphasize

dais mo to we th fr sa su mo to we th fr sa su mo to we th fr sa su mo to we th fr sa su mo to we th fr sa su

varm up Endurance x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x

Drils Technic/coordination x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x

Strength trainig

Phase 0 stability x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x

Phase 1 Strength endurance.

Phase 2 Maximum strength.

Phase 3 Strength-speed x x x x x x x x x x

Phase 4 Speed-strength x x x x x

Phase 5 Speed.

Runing(sprinting)

Endurance smalsidet games. Runnig

Speed endurance 85% Intesity* 20 -40m - sprints

top speed 100% Intesity 40m - 90m sprints

ecceliration 100% Intesity 20m - 40m sprints x x x x x x x x x x x x x x x

Plyometrics and agility

1

Light ankle jumps, and other jumps

.70% intensity x x x


2

low hurdle jumps, ankle and other

plyometrics 85% intesity x x x x x x


3

High hrdle jumps and other

plyometrcs 100% intensity x x x x x x

Sprt specific Technic football

Sprt specific Technic football

Flexibility cor+flexibility x X x x x x x X x x x x x x x x x x x x x x x x x x x x x x

128 9 10

Mesocycle 411

75

Practise 2.

This was second practice of the week that was done from week 8 to week 14. This exercise did not chance over the intervention program.

agility jump (agility ladder) with stop in ewery thurd (work 50 sec rest 10 sec)

pushup with one hand on football (work 50 sec rest 10 sec)

low bak exercise (work 50 sec rest 10 sec)

High knee lydts with dumbels/medicen ball (work 50 sec rest 10 sec)

Single leg Jump ower cones forward and to side (work 50 sec rest 10 sec)

situps/ normal plank (work 50 sec rest 10 sec)

jump ower hurdles 70 - 90 cm (work 50 sec rest 10 sec)

sittups situps with medicen ball (work 50 sec rest 10 sec)

vertical jump with medicen ball (work 50 sec rest 10 sec)

hurdle side suffle. With puse on the side 3sec (work 50 sec rest 10 sec)

Axe chop/Two hand overhead throw(midicen ball) (work 50 sec rest 10 sec)

reaction exercise (work 50 sec rest 10 sec)

76

Pictures of Exercises, to clarify how they are done. These exercises are done in practice 1

and 3 and the strength training program that they are used in, is shown in appendix 7.6. Not

all of the exercises are done in every practice session.

Single leg

squat

(the knee

should not

go medial

to the foot)

Reaction

exercise.

Jumping

and

landing on

one leg 3x

direct.

Clin

single leg

clin

jump on a

bench lend

on one leg

hold

balance,

down, lend

on both

77

step-up

with

weights

hanging

from the

bar

agility

jump

(agility

ladder)

with stop

in every

third

single leg

hip extend

from bench

lying on

back(knee

100°)

lunges;

front, 45°

lateral,

45°medial

side to side

jump

push up

with one

hand on

football

78

low back

exercise

High knee

lifts with

dumbbells/

medicen

ball

sit-ups

Sit-ups

with

medicen

ball

vertical

jump with

medicen

ball

79

Hurdle

side

shuffle.

With pause

on the side

3sec

Axe

chop/Two

hand

overhead

throw(med

icen ball)

Plank;

Back,

groin,

simple

Single leg

Jump over

cones

forward

and to side

80

7.5. Appendix. Strength training program for the control group

Strength training program for the control group.

The strength traning program was based on training with body weight medicine ball,

Kettle bells, big tires and dumbbells.

There were two training session per week and one extra training session were the

football player performed himself with instructions from the coach. This training

session was to work on weaknesses in strength.

In februar- mars the training session were high volume with medium intensity. The

training session were two in a strength training program and then one extra for the

football player to work on his weaknesses

In April May the volume decreased but the intensity was higher. The training

sessions was two in this period. Mid May there was only one

During the football season 2013 there were no planned strength training sessions.

There was some strength training in football practices mostly with own body weight.

But if there were long time between games then they did strength training sessions

but mostly with their own body weight

The purpose from the coach of the control group was to try to make the strength

training more sports specific to the game of football. Most exercises were multi-

joint exercises.

81

Exercises for the control group

These Exercises are not single joint exercises they are multi- joint exercises, so the

line between upper and lower body are not so clear. And many of these exercises

were taken in one strength training session, the whole body was trained in every

strength training session, with emphasis on either the lower part or upper part, at any

given time

For legs

Exercises Factors in training focus in training

Forleg runing up hill Strength endurance Bild up the strength endurance that it wil take to last one footbal game. Make the body more ready for more strength training

Runing in sand draging ketle bell

Strength endurence

Kettle bell Turkish Get-Up (Lunge style)

Strength endurance and core

Squats with ketel bels Srength Build a greater maximum strength to be able to take better advantage of the speed and power training

Singleleg squts Strength

Roling ower truck tires Sterngth

Front Squats With Two Kettle bells

Strength

Kettle bell Dead Clean Strength

Two-Arm Kettle bell Clean Strength speed The intesity is higher and there are more speed in the exercises. Geting redy for speed training

One-Arm Kettle bell Clean and Jerk

Strength speed

Kettle bell Sumo High Pull Strength speed

For upper body, cor, brest,back, sholder girldleand arms

Alternating Floor Press Strength Build a greater maximum strength to be able to take better advantage of the speed and power training

One-Arm Kettle bell Military Press To The Side

Strength

One-Arm Kettle bell Row Strength

Two-Arm Kettle bell Military Press

Strength

Standing and dragging kettle bell with rope using just arms

Strength

Double Kettle bell Snatch Strength speed The intesity is higher and there are more speed in the exercises. Geting redy for speed training

Kettle bell Hang Clean Strength speed

Sittups Core strength Very important to have a good strength of the middle section the body

Advanced Kettlebell Windmill Strength and cor

Sit-ups with medicen ball Core strength speed

Sit-ups with ketlebell Core strength

82

7.6. Appendix. The Intervention Program Week 8 to 13. There were three strength training sessions per week, two

strength training sessions with weights and one strength training session on the field,

were the athlete were working with medicine balls and own body weight. An

example of exercises was bounce dynamic stability for core, knee, hips and ankle,

speed, explosive power and acceleration. The field training session in every week was

always the same.

The following programs are the variation that took place from week 8 to 13. How the

changes were made in reps and sets.

Exercise Time/Reps/distance Sett Intesity/Speed Volume rest(sec) Training emphasize

Endurance jog/small sidet games 10 to 15 min 1 Low Low Preparation for practice

Lunge with and without rotation 10m 2 Low Low 20s

Walking high knee graps 10m 2 Low Low 20s

Walking high knee graps into

lunges 10m 2 Low Low 20s

Standing groin swings 5-10x 1 Low Low

Standing hamstring swings 5-10x 1 Low Low

fóta vinna ? ?

agility with coines.? ? ?

agility in agility ladder? ? ?

high kneeliftd ? ? ?

heel high ? ? ?

Sigle leg squat 10 on leg 4 High High 1-2 min

Clin 5 3 High High 1-2 min

single leg clin 5 on leg 3 High High 1-2 min

step-up with weigths hangin from

the barr 10 on leg 4 High High 1-2 min

explosive power, technique

sigle leg hipp extend from bench 10 on leg 4 Medium High 1-2 min

lunges; front, 45° lateral, 45°medial

6 3 Medium High 1-2 min

speed and technique focus on hip

stability

Raction exercise. 6 on leg 3 High Medium 1

agility jump (agility ladder) 18 on leg 4 High Medium 1

jump on a bench lend on one leg,

down on both 4 on leg 4 High Low 1

side to side jump 3 3 High Low 1

cool dawn jog 5 min 1 low

Crunches /Cycled crunches 25 - 40 4 Medium Medium 1

25 - 40 Medium Medium 1

plank: groin, glut med og simple

plank 10 2 Medium Medium 1

Back exercise 30 4

stretching hamstring 30 sec 1 low

stretching qutriceps 30 sec 1 low

stretching groin 30 sec 1 low

stretching gluteus 30 sec 1 low

stretching kalf 30 sec 1 low

general stretching 30 sec 1 low

Flexibility cor+flexibility

maintaining the length of the muscle.

The strength and stability of the back,

abdomen and hips Is. it ok to do

exercise after a football. Important to

stretch after each workout but the

abdomen and back is fine to do every

day but at least 3 to 4 x weekly.

explosive power has to do with the

timing of the muscle activity. Stability of

the knee and hips

increase rum of motion

Preparing for exercise usually do

football workouts not for lifting. Is an

alternative for lifting.

Strength

trainigStrength-speed

Plyometrics

Light ankle jumps, and

other jumps .70%

intensity

A good technique, speed and explosive

power. Also dynamic balance

speed and technic stability of the back

Practice 1 and 3

Dynamic stretchesvarm up

Drils Technic/coordination

83

Day 2 contact work rest sett rest/ sets

agility jump (agility ladder) with stop in ewery thurd 18 50 sek 10 sek 2 2 min

push up with one hand on football 50 sek 10 sek 2 2 min

low bak exercise 50 sek 10 sek 2 2 min

High knee lydts with dumbels/wedicen ball 50 sek 10 sek 2 2 min

single leg Jump ower cones forward and to side 16 50 sek 10 sek 2 2 min

situps/ normal plank 50 sek 10 sek 2 2 min

jump ower hurdles 70 - 90 cm 4 50 sek 10 sek 2 2 min

sittups situps with medicen ball 50 sek 10 sek 2 2 min

vertical jump with medicen ball 50 sek 10 sek 2 2 min

hurdle side suffle. With puse on the side 3sec 3 50 sek 10 sek 2 2 min

Axe chop/Two hand overhead throw(midicen ball) 50 sek 10 sek 2 2 min

reaction exercise 9 50 sek 10 sek 2 2 min

Make a ring in the field or in the hall should not take more than 24 to 28 minutes emphasis is placed on

speed and Explosive Power, focus on performing exercises correctly. These exercises are thought to bee

preventive for injurys, where all the exercises are with dynamic balancing factors. In this training sesion the

intensity is high

practise 2

84









foot work ? ?




heel high ? ? ?

Sigle leg squat 8 on leg 4 High High 1-2 min

Clin 5 3 High High 1-2 min

single leg clin 5 on leg 3 High High 1-2 min




sigle leg hipp extend from bench 10 on leg 4 Medium High 1-2 min


6 3 Medium High 1-2 min


stability






cool dawn jog 5 mín 1 low

Crunches /Cycled crunches 25 til 40 4 Medium Medium 1

25 til 40 Medium Medium 1



Back exercise 30 4









the knee and hips





abdomen and hips Is it ok to do exercise

after a football. Important to stretch

after each workout but the abdomen

and back is fine to do every day but at

least 3 to 4 x weekly.


Drils Technic/coordination Preparing for exercise usually do



Strength



Practice 4 and 6

varm upDynamic stretches


Plyometrics


other jumps .70%

intensity

85

















intensity is high

practise 2

86









foot work ? ?




heel high ? ? ?

Sigle leg squat 6 on leg 4 High medium 1-2 min

Clin 4,3,3 3 High medium 1-2 min

single leg clin 5 on leg 3 High medium 1-2 min




sigle leg hipp extend from bench 8 on leg 4 Medium m. High 1-2 min


6 3 Medium medium 1-2 min


stability











Back exercise 30 4


















Strength


Plyometrics


other jumps .70%

intensity



the knee and hips

Practice 7 and 9






87

















intensity is high

practise 2

88









foot work ? ?




heel high ? ? ?



single leg clin 5 on leg 3 High medium 1-2 min




sigle leg hipp extend from bench 8 on leg 4 Medium m. High 1-2 min




stability











Back exercise 30 4


















Strength


Plyometrics


other jumps .70%

intensity



the knee and hips

Practice 10






89

















intensity is high

practise 2

90









foot work ? ?




heel high ? ? ?



single leg clin 4,3,3 on leg 3 High medium 1-2 min


the barr 6 on leg 3 High medium 1-2 min


sigle leg hipp extend from bench 8 on leg 3 Medium medium 1-2 min




stability











Back exercise 30 4


















Strength


Plyometrics


other jumps .70%

intensity



the knee and hips

Practice 12






91

















intensity is high

practise 2

92









foot work ? ?




heel high ? ? ?











stability











Back exercise 30 4


















Strength


Plyometrics


other jumps .70%

intensity



the knee and hips

Practice 13






93

















intensity is high

practise 2

94









foot work ? ?




heel high ? ? ?











stability











Back exercise 30 4


















Strength


Plyometrics


other jumps .70%

intensity



the knee and hips

Practice 15






95

Preparation for the competition

Week 13 to 20. The program changes from three time’s strength training per week to

twice per week. On strength training practice with weights and one field practice

with bounce, dynamic stability, for core, knee, hips and ankle, also speed and

acceleration. The second strength training practice session in every week was always

the same, but the first one, varies in different exercise, reps and sets.

The following programs are the variation the first exercise per week.


Endurance jog/small sidet games 10 to 15 min 1 Low Low







Sigle leg squat 5 á on leg 3 High lov 1-2 min

Clin 4,3,3,3,3 3 verry High medium 1-2 min

single leg clin 4,3,3 on leg 3 High low 1-2 min

sigle leg hipp extend from bench 8 on leg 3 Medium medium 1-2 min Rapidly up but slowly down



down on both 2 on leg 3 High Low 1Bounce the low hurdles 50cm landing

last hurdle dash 5 to 10 m

4 hurdles 2 very high Low 1 mín

The last exercise. The aim is explosive

power and agility. NOTE soft under

layer. Dinah / grass

cool dawn skokk niður 5 min 1 low

Crunches /Cycled crunches 25 to 40 4 Low Medium 1


plank 10 2 Low Medium 1

Back exercise 30 4 Low medium 1




















Plyometrics


other jumps .70%

intensity



the knee and hips

week 13 and 14 Practice 1


Strength

trainigspeed - Strength-

96















reaction jump 6 on leg 3 High low 1
































Plyometrics


other jumps .70%

intensity



the knee and hips

week 15 and 16 Practice 1


Strength


97


Endurance jog/small sidet games 10 til 15 1 Low Low









6 on leg 3 High medium 1-2 min explosive power, technique






last hurdle dash 5 to 10 m4 hurdles 2 very high Low 1 mín



layer. Dinah / grasscool dawn jog 5 min 1 low

Crunches /Cycled crunches 25 til 40 4 Low Medium 1























Plyometrics


other jumps .70%

intensity



the knee and hips

week 17 practice 1


Strength


98


Endurance jog/small sidet games 10 to 15 1 Low Low







Sigle leg squat 5 on leg 3 High lov 1-2 min



































Plyometrics


other jumps .70%

intensity



the knee and hips

week 18 Practice 1


Strength


99














































Plyometrics


other jumps .70%

intensity



the knee and hips

week 19 Practice 1


Strength


100

The following program was the second exercise per week





Walking high knee graps into lunges 10m 2 Low Low 20s



single leg bounce left,left/right,right….. 10m 3 verry High medium 1 min

triple bounce left,right………… 10m 3 verry High medium 1 min

doble leg bounse 10m 3 verry High medium 1 min

bounce up in ewery step up high 20m 3 verry High medium 1 min

bounce forvard in every thurd 20m 3 verry High medium 1 min

hurdle bounce 50 to 70 cm 4 4 verry High medium 1 min

push up with one hand on football 25+ 4 Medium medium 1 min

situps/ normal plank 30 til 50 3 Medium medium 1 min

agility jump (agility ladder) 4 4 Medium medium 1min

High knee lydts with dumbels/wedicen ball10 steps 4 Low Low 30sec

hurdle side suffle. 4 3 Medium Low 1

single leg Jump ower cones forward and

to side 1 4 Medium Low 20 sek



25 til 40 Low Medium 1

plank: groin, glut med og simple plank 10 2 Low Medium 1
















Week 13- 20 exercise 2

varm up

Dynamic stretches

Plyometrics

(speed-

strength)

jumps, and

stabilisation 70%-100%

intensity



Stability, balance, strength and

prevention exercises.




101

Programs during the competition

There were changes in the frequency of strength and power exercise per week in

competition from week 20 to 28. The practice sessions were one to two per week; it

depended on the frequency of games. There were fewer exercises per training day

and the max time took 30 min

The following programs were the variation the first exercise per week.













































Plyometrics


other jumps .70%

intensity



the knee and hips

week 20 and 21 practice 1


Strength


102












situps/ normal plank 30 to 50 3 Medium medium 1 min


High knee lydts with dumbels/medicen ball 10 steps 4 Low Low 30sec


Hopp yfir keilur fram og til hliðar 1 4 Medium Low 20 sek



















week 20 and 21 Parctice 2


Plyometrics

(speed-

strength)

jumps, and


intensity

explosive power and agility. NOTE soft

substrate. Dinah / grass. Dynamic

balance, bounce hurdle and sprinting 5

to 10 m. after last contact






103











Sigle leg squat 6 on leg 3 High medium 1-2 min explosive power, technique



Bounce the low hurdles 50cm landing

last hurdle dash 5 to 10 m3 hurdle 2 very high Low 1 mín














week 21 - 28 exercise 1


Strength







Plyometrics


other jumps .70%

intensity



the knee and hips









104











Sigle leg squat 6 on leg 3 High medium 1-2 min explosive power, technique




last hurdle dash 5 to 10 m3 hurdle 2 very high Low 1 mín



























Plyometrics


other jumps .70%

intensity



the knee and hips

week 22 - 24 practice 1


Strength


105



































week 25 Parctice 1


Plyometrics

(speed-

strength)

jumps, and


intensity










106












































Plyometrics


other jumps .70%

intensity



the knee and hips

week 26 exercise 1


Strength


107



































week 26 Parctice 2


Plyometrics

(speed-

strength)

jumps, and


intensity










108












































Plyometrics


other jumps .70%

intensity



the knee and hips

week 27 exercise 1


Strength


109

Strength training practice sessions, in mid-season to the end of the season

In mid-season to the end of the season: from week 28 to 38. The strength and power

practice sessions were only one per week.

The following program were


Endurance jog/small sidet games 10 til 15 1 Low Low






Clin 4,3,3,3, verry High medium 1-2 min


bounce forvard in every thurd 50sek/10 rep 2 verry High medium 1 min


situps/ normal plank 30 til 50 3 Medium medium 1 min

agility jump (agility ladder) 18 on leg 4 Medium medium 1min

High knee lydts with dumbels/wedicen ball 10 step 4 Low Low 30sec


single leg Jump ower cones forward and to side 1 4 Medium Low 20 sek



25 til 40 Low Medium 1

















week 28 - 38 exercise 1


Plyometrics

(speed-

strength)

jumps, and


intensity










110

7.7 Appendix. Spurningarlisti áður en mælingar eru

framkvæmdar Númer: _________

Spurningarlisti áður en mælingar eru framkvæmdar

1. Aldur: _______

2. Hæð: ________

3. Þyngd: ________

4. Ríkjandi fótur:

[ ] Hægri

[ ] Vinstri

5. Staða á velli:

[ ] Markmaður

[ ] Sóknarmaður

[ ] Varnarmaður

[ ] Kantmaður

[ ] Miðjumaður

6. Hversu lengi hefur þú stundað knattspyrnu (í árum)? _______

7. Hefur þú meiðst við íþróttaiðkun

[ ] Já

[ ] Nei (spurningu 8 sleppt)

8. Merktu við þau meiðsli sem þú hefur orðið fyrir í töflunni hér

fyrir neðan. Tilgreindu um hvorn fótinn var að ræða, hvenær

meiðslin áttu sér stað, við hvaða aðstæður meiðslin komu

fram og hve lengi þú varst frá æfingum og/eða keppni. Auk

þess hvort að leitað var til heilbrigðiskerfisins vegna

meiðslanna (læknir, sjúkraþjálfari osfrv). Reyndu að vera eins

nákvæmur og kostur er.

111

Ökklameiðsli Hvaða

fótleggur?

Hvenær

(dagur,

mánuður, ár)?

Aðstæður (í keppni, við æfingu, samstuð við

annan leikmann o.s.frv.)?

Hve lengi frá

æfingum/keppni (fullfær

um að taka þátt í æfingum

og geta tekið þátt í

leikjum)?

Tegund meiðsla?

[ ] Slit á liðbandi [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys

[ ] Gömul meiðsl taka

sig upp að nýju

[ ] Annað

Hvað?________

[ ] Tognun á liðbandi [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Hásinaslit [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

112

[ ] Álagsmeiðsl á hásin [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Annað? ______________ [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

Hnémeiðsli Hvaða

fótleggur?

Hvenær

(dagur,

mánuður, ár)?



Hve lengi frá




leikjum)?

Tegund meiðsla?

113

[ ] Fremra krossbandaslit [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Fremra krossbandaslit [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Aftara krossbandaslit [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Slit á liðbandi [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

114

Hvað?________

[ ] Tognun á liðbandi [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Liðþófaskaði [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Annað? ______________ [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

Mjaðmameiðsli Hvaða

fótleggur?

Hvenær

(dagur,

mánuður, ár)?



Hve lengi frá




Tegund meiðsla?

115

leikjum)?

[ ] Tognun í nára [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Slit á liðböndum [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Tognun á liðböndum [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Álagsmeiðsl í nára [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] Álagsmeiðsl

[ ] Slys


116

[ ] 8-28 dagar

[ ] > 28 dagar

sig upp að nýju

[ ] Annað

Hvað?________

Vöðvatognun Hvaða

fótleggur?

Hvenær

(dagur,

mánuður, ár)?



Hve lengi frá




leikjum)?

Tegund meiðsla?

[ ] Hvar?______________ [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Hvar?______________ [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Hvar?______________ [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

117

[ ] > 28 dagar Hvað?________

Beinbrot Hvaða

fótleggur?

Hvenær

(dagur,

mánuður, ár)?



Hve lengi frá




leikjum)?

Tegund meiðsla?

[ ] Hvar?______________ [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Hvar?______________ [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Hvar?______________ [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

118

Önnur meiðsli Hvaða

fótleggur?

Hvenær

(dagur,

mánuður, ár)?



Hve lengi frá




leikjum)?

Tegund meiðsla?

[ ] Hvað?______________ [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Hvað?______________ [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

[ ] Hvað?______________ [ ] Hægri

[ ] Vinstri

[ ] Báðum

Dagar:______

[ ] 0 dagar

[ ] 1-3 dagar

[ ] 4-7 dagar

[ ] 8-28 dagar

[ ] > 28 dagar

[ ] Álagsmeiðsl

[ ] Slys


sig upp að nýju

[ ] Annað

Hvað?________

119

7.8. Appendix. Meiðslaskýrsla eftir tímabil

Nafn

Dags útfyllt:

1A Dags meiðsla/slyss:

1B Dags þegar leikmaður varð aftur leikhæfur:

2A Líkamspartur sem varð fyrir meiðslum/slysi:

Öxl/viðbein

Upphandleggur

Olnbogi

Framhandleggur

Úlniður

Hönd/fingur/þumall

2B Líkamspartur sem varð fyrir meiðlsum/slysi

Vinstri

3

Heilahristingur með eða án meðvitundarleysis Skemmd á liðþófa eða brjóski

Vöðvaáverki/tognun/rifa/krampi

Sinameiðsli/áverki/sinabólga/sinaslíðrabólga

Blæðing í vöðva eða lið/marblettur

Núningssár

Sár/skurður

4 Greining (nánari lýsing á meiðslum; t.d greining læknis/sjúkraþjálfara ef við á):

5 Er um að ræða sömu meiðsli og leikmaður hefur áður glímt við (sama tegund og sömu hlið):

Nei

Ef já, tilgreinið hvenær leikmaður varð leikhæfur aftur vegna fyrri meiðsla (dags):

6 Er um að ræða álagsmeiðsl eða slyss:

Álagsmeiðsl Slys

7 Við hvaða aðstæður komu meiðslin fram:

Æfing Í leik

8 Komu meiðslin til vegna samstuðs eða snertingar:

Já, við annan leikmann

Já, vegna annara hluta (tilgreinið nánar):

9 Ef leikmaður meiddist í leik var aðdragandi meiðslanna brot sem dæmt var af dómara:

Já, aukaspyrna/vítaspyrna

Ef já, var dæmt á:

Andstæðing

Meiðslaskýrsla

Tognun á liðböndum/liðbandameiðsli

Önnur meiðsli (tilgreinið nánar):

Ökkli

Lið: Fylkir

Númer:

Nei Já, vegna bolta

Þig (leikmann sem meiddist)

Mjóbak/spjaldbein/mjaðmagrind

Hægri

Tegund meiðsla/slyss:

Beinbrot

Annars konar beinmeiðsli (t.d beinmar)

Fara úr lið að öllu leyti eða hluta til

Taugaskaði

Tannskaði

Á ekki við

Fótur(rist)/tær

Já, rautt spjald

Nei

Höfuð/andlit

Háls/efri hluti hryggsúlu

Bringubrein/rif/efra bak

Kviður Neðri útlimir/hásin

Hné

Læri

Mjöðm/nári

Já

Já, gult spjald

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