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Research in Sports MedicineAn International Journal

ISSN: 1543-8627 (Print) 1543-8635 (Online) Journal homepage: http://www.tandfonline.com/loi/gspm20

The Influence of Soccer Shoe Design on PlayerPerformance and Injuries

Ewald M. Hennig

To cite this article: Ewald M. Hennig (2011) The Influence of Soccer Shoe Design on PlayerPerformance and Injuries, Research in Sports Medicine, 19:3, 186-201

To link to this article: http://dx.doi.org/10.1080/15438627.2011.582823

Published online: 04 Jul 2011.

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Research in Sports Medicine, 19:186–201, 2011Copyright © Taylor & Francis Group, LLCISSN: 1543-8627 print/1543-8635 onlineDOI: 10.1080/15438627.2011.582823

REVIEW PAPERS

The Influence of Soccer Shoe Design on PlayerPerformance and Injuries

EWALD M. HENNIGBiomechanics Laboratory, Institute of Sport and Movement Sciences, University

Duisburg-Essen, Essen, Germany

Although soccer is the most popular sport in the world, littleresearch has been published in the field of soccer biomechanics,particularly on the importance of footwear for the game. The trac-tion properties of soccer shoes on natural and artificial turf havebeen speculated to be responsible for acute and chronic injuriesin soccer. This article reviewed the current knowledge on how soc-cer shoes influence the risk of injuries and how they may serve toimprove player performance. Comfort is the highest priority thatplayers want from their shoes, followed by traction and stability.Cleat design and arrangement are important shoe features thatallow for fast accelerations and stops, rapid cuts, and turns. Soccershoe design can influence shooting speed and, even more impor-tant for the game of soccer, kicking accuracy. To combine shoecharacteristics for injury prevention and better performance willbe a challenge for future research on optimizing soccer shoes.

KEYWORDS soccer shoes, injury protection, kicking speed, kick-ing accuracy, traction, artificial turf

INTRODUCTION

Soccer is the most watched, most played, and most revenue-generating sportin the world. In 2006, the International Federation of Association Football

Received 19 February 2011; accepted 11 March 2011.Address correspondence to Ewald M. Hennig, Biomechanics Laboratory, Institute of

Sport and Movement Sciences, University Duisburg-Essen, Gladbecker Str. 182, 45141 Essen,Germany. E-mail: ewald.hennig@uni-due.de

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Influence of Soccer Shoe Design on Performance and Injuries 187

(FIFA) performed a worldwide survey to estimate the number of soccerplayers (Kunz, 2007). According to this survey 265 million (4% of the worldpopulation) active players were counted. Approximately 15% (4.1 million)of these players are women, and the number of registered female playershas increased by 54% between 2000 and 2006. As compared with the wealthof literature for the biological aspects of soccer, biomechanical research hasreceived little attention. A good summary about the biomechanics of kickingrecently has been published by Lees, Asai, Andersen, Nunome, and Sterzing(2010). From almost 10,000 scientific papers, Shephard (1999) selected370 publications for a review on the biology and medicine of soccer. Thisreview focuses on physiological, biochemical, and anthropometric aspectsof male and female soccer players. Although incidence and prevention ofinjuries is included in this review, little attention has been given to the roleof footwear in influencing the performance and injury risk of soccer players.Players need good skills in handling the ball during receiving, running withthe ball, and kicking. Quickness on the field with rapid accelerations andstops has become very important in modern soccer. Footwear helps theplayer to perform these fast movements on the field. It is surprising howlittle literature has been published in the field of soccer shoe research. Thepurpose of this article is to summarize the effect of soccer shoe design onplaying performance and injury incidence. In several studies our laboratoryexplored the properties of footwear on comfort, traction, ball velocity, andkicking accuracy. Furthermore, the influence of shoe and playing surfacewill be discussed.

WHICH SHOE FEATURES DO PLAYERS WANT?

Soccer shoes have changed considerably in recent years. During the earlydays, English factory workers used hard leather workboots for playing.Later, football boots replaced the workboots by adding leather studs to theoutsole for better traction. These early soccer boots had a mass of more than500 g, which could increase to more than 1 kg in wet weather conditions.During the world championship in 1954, Adi Dassler developed shoes forthe German national team with a low weight of only 380 g. For protectionpurposes, the early soccer shoes had a high shaft, covering the ankle. In the1960s, below-the-ankle football shoes were introduced. An improvementin synthetic materials brings the weight of modern soccer shoes down toless than 200 g. From the historic developments, it is obvious that providinggood traction and low weight are desirable properties that the playersexpect from their shoes.

Using a questionnaire, our laboratory performed two surveys in 1998and 2006 to determine the most desirable features that players expect fromtheir footwear. From a list of 11 shoe properties on the questionnaire, thesubjects ranked their five most-liked shoe characteristics from most (1) to

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least important (5). All shoe properties that were not chosen by the playersreceived a score of “6.” The mean results from both surveys are summarizedin Figure 1. From the 1998 questionnaire, answered by 250 male soccer play-ers, shoe comfort had by far the highest priority, followed by stability in theshoe and good traction on the field (Hennig, 2006). Ball sensing or touchof the ball also was ranked high in the priority list. We used the same ques-tionnaire for the second survey in 2006 for 73 male and 69 female soccerplayers. When comparing the results of both surveys for the men, stability,traction, and a low shoe weight became in 2006 even more important forthe players. In recent years soccer developed toward a more powerful andfaster game. Fast movements of the players on the field can be improved bygood traction, stability, and a low weight shoe. Therefore, it is not surprisingthat these shoe properties received better rankings from our players in 2006.The preferences of our female players in the 2006 survey were very similarto those of the men. Only traction and low shoe weight were not as impor-tant for the women, and injury protection was felt more important by ourfemale players. This can be explained by the difference in playing behaviourbetween female and male soccer players. As reported by Althoff et al. (2010),women’s soccer is less aggressive and slower. In spite of a less aggressiveplay, however, women have a much higher incidence of anterior cruciateligament (ACL) injuries than men (Arendt, Agel, & Dick 1999). Therefore,shoes with lower traction are not as much needed for female players andalso may reduce the injury risk. Because soccer players want their shoes tofit like a glove, special attention has to be given to the female foot anatomy

FIGURE 1 Soccer player ranking of most desirable shoe properties (lowest value = bestrating).

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Influence of Soccer Shoe Design on Performance and Injuries 189

for gender-specific shoes lasts (Krauss, Valiant, Horstmann, & Grau, 2010).In general, it is surprising how little importance the shoe feature “injuryprotection” on our questionnaire received by both our male and femaleplayers. Although there is a high incidence of soccer injuries, performancecriteria are dominating when soccer players choose their favourite shoes.This is documented by light weight, low cut, and high-traction-providingfootwear, as it is seen today in modern soccer. Considering the high inci-dence of ankle injuries (Fong, Hong, Chan, Yung, & Chan, 2007), we notethat modern soccer shoe properties certainly increase the risk of sufferingankle sprains. These shoes have very little in common with the original soc-cer shoes, as they have evolved from the working boots of English factoryworkers.

INJURIES IN SOCCER—THE ROLE OF SHOESAND PLAYING SURFACES

Injury rates are much higher during games as compared with practices insoccer (Agel, Evans, Dick, Putukian, & Marshall, 2007; Babwah, 2009) aswell as American football (Yard & Comstock, 2009). A prospective study on266 elite players from five European countries found 30.5 soccer injuriesfor 1,000 playing hours in a match and 5.8 injuries for 1,000 training hours(Walden, Hagglund, & Ekstrand, 2005). Fifteen percent of these injuries wereserious, resulting in an absence of the players for more than 4 weeks. Fora period of 15 years from 1988 to 2003 collegiate men´s soccer injurieswere recorded (NCAA injury surveillance) and analysed in the United States(Agel, et al., 2007). These authors reported a four times higher incidence ofinjuries during games as compared with practices. Almost 70% of all injurieswere located in the lower extremities. During games, player-to-player con-tact was the primary cause for an injury, whereas during practices mostinjuries occurred in a noncontact situation. Ankle sprains were overall themost common injury, and most often severe injuries to the player werewith the Knee. A similar NCAA injury surveillance between 1988 and 2003looked at the injury type and rate for women´s soccer (Dick, Putukian, Agel,Evans, & Marshall, 2007). The injury rate for the women was also approxi-mately three times higher during games as compared with practices. Again,the lower extremities were affected (70%), and ankle sprains were the mostcommon injury (18.3%). In game situations, internal derangement of theknee caused more injuries for the female players (15.9%) as compared with11.0% for male soccer players (Agel, et al., 2007). Data from both NCAA stud-ies show that the frequency of ACL knee injuries was 2.4 times higher for thewomen (Arendt, et al., 1999) for the same number of athlete contact expo-sures. In a recent literature review, based on 33 article on the topic of genderspecific ACL injuries, Walden, Hagglund, Wemer, and Ekstrand (2011) came

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to the conclusion that female players have a two to three times higher injuryrisk than their male counterparts. The increased risk of ACL injuries amongwomen is likely multifactorial, including intrinsic and extrinsic factors. Tothe intrinsic factors belong muscle strength, limb alignment, ACL size, liga-mentous laxity, intercondylar notch dimensions, hormonal influences, andmuscle imbalance between quadriceps and hamstring muscles (Arendt, et al.,1999; Anderson, et al., 2001). Extrinsic factors like movement patterns andthe type of coaching however, seem also to play a role. Many researchersbelieve that the type of footwear as well as playing surface have an influenceon injury risks in soccer. It appears obvious that shoes and surfaces that pro-vide high traction during cutting and turning movements will increase therisk of ankle sprains. Similarly, it is believed that a high torsional resistancefor the forefoot during turning movements will cause a higher risk of kneeinjuries.

SOCCER INJURIES AND TRACTION

There is surprisingly little or no evidence that there is a relationship betweentraction properties and injury risk. Several studies on the effect of artificialturf on injuries revealed controversial results. Some found increased andothers reduced injury risks, playing on artificial turf as compared with nat-ural grass surfaces. Most of these studies were not prospective, had a lownumber of subjects, and used different artificial turf surfaces from differ-ent generations. A prospective study by Ekstrand, Timpka, and Hagglund(2006) compared the injury patterns from 290 elite players of 10 Europeansoccer clubs training on artificial turf with 204 elite players training on natu-ral grass. There was no difference in injury frequency and severity betweenthe two groups in game situations or during practices on the two surfaceconditions. More recently, Ekstrand, Hagglund, and Fuller (2010) reported aprospective study with 15 men and 5 women soccer teams, playing matcheson third-generation artificial turf. A comparison to data when playing onnatural grass showed no difference in the overall injury risk between maleand female players in match and practice situations. During matches, how-ever, the male players had a reduced risk of quadriceps strains and a higherrisk of ankle sprains on artificial turf. It appears that the overall rate is thesame between the two surface conditions, but the pattern of injuries maychange.

As mentioned before, many researchers speculate that injury risks arerelated to the traction behaviour of the shoe-to-surface interface. This isespecially true for the resistance against forefoot rotation. It is a commonbelief in the soccer shoe industry that the soccer shoe should offer goodtraction for acceleration and cutting movements on the field. For rotationalmovements of the forefoot, however, traction should not be high. Using

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a mechanical testing apparatus to mimic turning movements on the fore-foot, Villwock, Meyer, Powell, Fouty, and Haut (2009) tested 10 differentsoccer shoe models on Field Turf, AstroPlay, and two natural grass sur-faces. The authors found higher peak torques and rotational stiffness forboth artificial surfaces. Furthermore, the influence of the artificial surfacewas much larger than the effect of the shoe cleat patterns between the10 different soccer shoe designs. From these results it appears surpris-ing that there is little influence of the traction behaviour on the risk ofinjuries.

A possible explanation for this phenomenon is an adaptation behaviourof the player to the traction conditions on the field. In a comparison of play-ing on artificial turf against natural grass (Andersson, Ekblom, & Krustup,2008) examined ball skills and movement patterns of Swedish male andfemale elite soccer players. The players also filled out a perception ques-tionnaire. The authors reported no differences in total covered distance ina game, speed profiles of the players, and number of sprints. There werefewer sliding tacklings and more short passes, however, on artificial turf.The players reported a worse overall impression and poorer ball control forplaying on artificial turf. Thus, there is an adaptation of movement patternsto the playing surface. Mueller, Sterzing, Lange, and Milahi (2010) combinedmechanical testing, perception ratings, biomechanical evaluations, and per-formance scores on four soccer shoes with different outsole cleat designs.The experiments were performed on a FIFA third-generation artificial turf.For acceleration, cutting, and turning movements, ground reaction forcesshowed large differences, especially for the shear force parameters. Theshoe (soft ground plate design) with the lowest peak shear force in the cutand turn movements also had the worst performance time on a predefinedslalom course. The perception ratings from the subjects also identified thesoft ground shoe as footwear with the worst performance. Shear groundreaction force parameters and the dynamic coefficient of friction were men-tioned by various authors as the most important variables to identify thetraction characteristics of soccer shoes (Shorten, Hudson, & Himmelsbach,2003; Valiant, 1988). Studies from our laboratory (Althoff, Hennig, & Hömme,2009) confirm these results by exploring the time of greatest likelihood fora slip to occur (Figure 2).

This graph represents typical ground reaction forces for a fast turningmovement and the derived coefficient of slipping. Due to small forces atinitial force platform contact the dynamic slipping coefficient is meaninglessfor the first 20 to 30 ms (dashed shaded area). After approximately 100 ms,the risk for a slip is greatest for a duration of about 180 ms (grey shadedarea) and is lower thereafter. From our studies the risk of slipping for cutting,rapid turns, and sudden stop movements was found to be highest shortlyafter ground contact.

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FIGURE 2 Typical dynamic slipping coefficient for a fast turning movement (270 degrees) ina soccer shoe.

SOCCER SHOE DESIGN AND PLAYER PERFORMANCE

Comfort was ranked highest in the features that players expect from theirshoes (Figure 1). Obviously, comfort is linked to player performance. In anuncomfortable shoe, pain and discomfort will prevent players from showingtheir best performance. It has been shown that in-shoe pressures under thefoot can very well be perceived by subjects (Milani, Hennig, & Lafortune,1997). In walking, plantar and dorsal foot pressures are closely related to theperception of comfort (Jordan & Bartlett, 1995). For running shoes, plantarand dorsal pressure related variables were also found to have a close link tooverall comfort ratings of subjects (Chen, Nigg, & De Koning, 1994; Hagen,Hoemmer, Umlauf, & Hennig, 2010).

PLANTAR RESSURE DISTRIBUTION IN SOCCER SHOES

Eils et al. (2004) looked at the in-shoe foot pressures for four soccer-specific movements: running, sprinting, cutting, and shots on goal. They

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FIGURE 3 Mean peak pressures during cutting movements of 18 subjects in four differentshoe constructions.

found substantial differences in the loading patterns between the differentmovement but no differences between a grass and cinder playing surface.Eils et al. (2004) and Wong, Chamari, Mao de, Wisloff, and Hong (2007)concluded from their pressure distribution studies that the medial side ofthe plantar surface may be more prone to injuries in soccer. The influenceof shoe design on the plantar pressure distribution patterns during soccer-specific movements was tested in our laboratory with 18 male subjects. Thepressures were measured during running, cutting movements, and kickingin four different shoe constructions. Similar to the results of Eils et al. (2004)and Wong et al. (2007), we found high medial forefoot pressures duringcutting movements of our subjects (Figure 3).

High peak pressures under the first metatarsal head are apparent,demonstrating a substantial medial forefoot loading during fast cutting move-ment. These elevated loads may explain the high incidence of first raydisorders in soccer players, as reported by Nihal, Trepman, and Nag (2009).

TRACTION PROPERTIES AND PERFORMANCE

After comfort, traction and shoe stability are the most important proper-ties that players expect from their shoes (Figure 1). The value of soccershoe traction property measurements is very limited when using mechanicaldevices that try to mimic the traction properties of shoes for players on thefield. There is no uniform pressure distributions across the foot (Figure 3).With different movements, time dependent plantar pressure patterns willoccur that are dependent on foot structure, body weight, and the dynamic

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nature of the movement. Moreover, there is a neuromotor adaptation to theshoe and its properties by the soccer player. For these reasons, it is almostimpossible to simulate or reproduce the mechanical loading of the foot by amechanical device. Therefore, we use a functional traction course test (FTC).The principle behind this test is very simple. As mentioned before, playerswill adjust their movements to the traction properties of the shoe to groundinterface conditions. If the ground is slippery, the players will run more cau-tiously and perform their movements slower. A simple time measurement forrunning through a given slalom course provides valuable information on thetraction properties of shoes on a given surface. Such a course should consistof parts including straight accelerations and decelerations as well as a slalomsection providing multiple cutting and turning movements. Sterzing, Kroiher,and Hennig (2009a) have given an example for such a course and reportedresults from eight different soccer shoe traction studies that were performedbetween 2002 and 2007. Especially, the slalom times with cuts and turnswere affected most by the shoe-to-ground interface conditions. For a shoewith no cleats, running time through the course was increased by 26%.Running on different surface conditions (ice and snow versus dry firm grass)resulted in running time differences of approximately 20%, and modifyingstud type and/or geometry resulted in about 3% performance differences.

SHOE DESIGN AND ITS INFLUENCE ON MAXIMUMBALL VELOCITY

Contact time between foot and ball during full instep power kicks is lessthan 10 ms (Nunome, Lake, Georgakis, & Stergioula’s, 2006). Due to theshort impact time and a large momentum transfer high peak forces of almost3,000 N were found with high speed videography at 5,000 Hz (Shinkai,Nunome, Isokawa, & Ikegami, 2009). These authors also observed that dur-ing the impact phase the foot was forced into an abducted, everted, andplantarflexed position. Tsaousidis and Zatsiorsky (1996) reported that thefoot-to-ball interaction cannot be modeled as a pure impact situation. It isalso determined by a throwing-like movement. The foot follows the ball afterfirst contact for more than 25 cm. The authors suggest that more than 50%of the ball’s speed is determined without the contribution of the potentialenergy from ball deformation. Achieving high ball velocities is important fordistance shots on the goal. These situations do not occur often in a gamebut are very important. To achieve high ball velocities is primarily depen-dent on the skill of the player and his striking technique. Muscle strength andanthropometric characteristics of the player also determine ball speed andare reasons for higher ball speeds in male compared with female players.Only few soccer players believe that a shoe can help them in improvingmaximum ball velocity. This may be the reason why soccer players ranked

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maximum ball speed in our questionnaire (Figure 1) of desirable shoe prop-erties very low. Sterzing and Hennig (2008) did a number of experimentsto investigate the influence of soccer shoe properties on kicking speed. Abetter shoe traction for the stance leg was found to improve kicking speed,but outsole stiffness and shoe mass did not have an influence. Amos andMorag (2002) reported increased foot velocities during kicking in shoes witha lower mass. They did not determine maximum ball velocity. Measuringball velocity in our studies, we did not find an increase of maximum ballvelocity with a lower shoe mass. Therefore, the momentum transfer fromthe foot to the ball must have remained the same. Apparently, a higher shoemass compensates for the lower foot velocities and thus creates a similarmomentum. The shoe upper material properties can reduce ball velocity byup to 1.2% if friction between ball and the upper material is very low ortoo high. In a low friction situation energy can be lost by slipping of theball across the shoe upper and when friction is high, additional spin to theball will be generated (Asai, Carre, Akatsuka, & Haake, 2002), thus reducingits translational energy. Outsole stiffness and elasticity has been suspectedto have an influence on maximum ball speed by providing extra energythrough a rebound mechanism of the outsole. We were not able to find,however, an influence of the mechanical outsole properties on ball speed.Plagenhoef (1971) reported a case study showing a player could kick fur-ther without shoes. This observation was not followed up by a scientificstudy. In our barefoot study we found the same surprising result (Sterzing,Kroiher, & Hennig, 2009b) of higher ball velocities in a barefoot condition.Even though barefoot kicking is much more painful, our players achievedhigher maximum ball speeds. A high-speed video analysis showed that theplayers have a higher degree of foot plantarflexion during barefoot kicking.This will cause a stronger mechanical coupling between the foot and thelower leg, resulting in an increased effective impact mass.

SHOE DESIGN AND ITS INFLUENCE ON KICKING ACCURACY

Kicking accuracy for passing and shots on goal is one of the most importantskills for success in soccer games. Few soccer players would believe thata shoe can influence their kicking precision. This may be the reason whyonly recently a scientific study has examined the influence of shoe designon kicking accuracy (Hennig, et al., 2009). Before exploring possible mech-anisms to increase kicking precision by footwear design, we performed apreliminary accuracy kicking study with five commercially available soccershoes and barefoot. To measure kicking accuracy, a custom-made electronictarget with a circular diameter of 120 cm was developed. Twenty-four sub-jects had the task of kicking on this electronic target from a distance of 10 m.The target centre was 115 cm above the ground. The subjects were asked

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FIGURE 4 Kicking accuracy (in cm from target center) in 6 different footwear conditions(++, ∗∗p < 0.01; +, ∗p < 0.05) (color figure available online).

to use their own technique to achieve best shooting accuracy. The meanaccuracy from 20 repetitive kicks was determined in each of the five shoesand barefoot condition for all subjects. To avoid pain during the barefootkicks, tight elastic socks were worn by the subjects.

As shown in Figure 4, barefoot kicking had by far the least accuracy.It showed a deviation of approximately 20% against the result gained withthe best accuracy shoe. Between the five shoe models, differences of morethan 10% were present. To explore the mechanisms behind these substan-tial differences in kicking accuracy, we conducted a series of studies toexamine some hypotheses for better kicking precision. Possibly, more fric-tion between the shoe and the ball will prevent slipping during contact andthus cause better precision. More friction between shoe and ball will alsocause increased spin of the ball, causing a more stable path of flight in theair. In a study, covering the same shoe with four materials, showing differ-ent coefficients of friction, did not result in changes of kicking accuracy.Touch of the ball—or good skin sensation—is a high priority for soccerplayers. This also could be a factor, therefore, for better shooting precision.Our data on barefoot (with socks) kicking, however, showed that the feelfor the ball is not a likely or is only a small factor to influence kickingaccuracy.

Based on our first study, we started thinking about the large differ-ences between barefoot versus shod kicking and came up with the followinghypothesis. The bony prominences of the foot create local pressure peaksand will cause a nonhomogeneous pressure distribution pattern. Coveringthe anatomical prominences with shoe material, the local pressure peaksare distributed across a larger area and may result in a more homogeneouspressure distribution. To test this hypothesis, we used a Pedar (Novel Inc.)

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pressure distribution measuring insole and positioned it on the upper oftwo different shoes (Hennig, et al., 2009). Using an elastic rubber band, theinsole was positioned and fastened to the medial mid- to forefoot of theshoe, where players hit the ball during instep kicks. We selected models Band C from our first study (Figure 4) for the measurements. Twenty subjectsperformed 20 repetitive shots for best accuracy on our electronic target. Toincrease the measuring frequency, only every second pressure distributionsensor in the forefoot region was sampled, resulting in a frame rate of 571Hz. The pressure measuring pads were adjusted on top of the shoes tothe foot anatomy, guaranteeing that all sensors were matched to identicalanatomical locations of the individual feet.

Figure 5 shows the average peak pressure distribution of the 20 sub-jects in the two shoe models. The centre of pressure, as indicated by thedark circle, changed from shoe B to C slightly more medial and posterior onthe foot dorsum. Furthermore, the pressures are more evenly distributedacross the ball contact area. Summing up the peak pressure differencesbetween adjacent transducers, shoe B has a value that is almost 20% higheras compared with the summed value of shoe C. From these results and fur-ther experiments we concluded that the homogeneity of pressure betweenthe shoe upper and the ball is the primary factor that influences kickingaccuracy.

CONCLUSION

Shoe comfort is the most important feature that soccer players expect fromtheir shoes. Performance rather than injury protection related shoe proper-ties receive a much higher preference from both male and female soccerplayers. There is little evidence that traumatic or overuse injuries are relatedto the different traction conditions for artificial turf against natural grass.A likely explanation for this surprising fact is an adaptation of movementbehaviour that soccer players chose to adjust to different traction condi-tions. In shoes providing better traction, soccer players move faster on thefield. This is the basis of a functional traction test that delivers valuableinformation for the design of soccer shoe outsoles. Pressure distributionmeasurements do not only serve to design more comfortable shoes but arealso used to understand the loading of the foot during different soccer-specific movements. From this knowledge, strategic cleat placement canserve to improve the traction behaviour of the shoe during different move-ments. Maximum ball velocity as well as kicking accuracy can be influencedby the shoe construction. Surprisingly, soccer players achieve higher maxi-mum ball speeds when kicking barefoot. Precision of passing and for kickson goal is very important in soccer. Soccer shoe design can help to improvekicking accuracy by a suitable shoe upper constructions. Reducing contact

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FIGURE 5 Mean peak pressures (N/cm2) between shoe and ball for shoes with less (A) andbetter (B) kicking precision.

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pressure inhomogeneity between the shoe and the ball will increase theprecision of shooting. Soccer shoe research is an interesting field that is stillin its infancy. Combining various shoe features to optimize performance andalso protect the player from injuries is a challenging task for the future.

REFERENCES

Agel, J., Evans, T. A., Dick, R., Putukian, M., & Marshall, S. W. (2007). Descriptiveepidemiology of collegiate men’s soccer injuries: National Collegiate AthleticAssociation Injury Surveillance System, 1988-1989 through 2002-2003. Journalof Athletic Training, 42, 270–277.

Althoff, K., Hennig, E. M., & Hömme, A.-K. (2009). Analysis of slip events duringsoccer specific movements. Footwear Science, 1(Suppl. 1), 13–14.

Althoff, K., Kroiher, J., & Hennig, E. M. (2010). Soccer game analysis of two worldcups—playing characteristics of women and men—and possible consequencesfor gender specific soccer shoes. Footwear Science, 2, 51–56.

Amos, M., & Morag, E. (2002). Effect of shoe mass on soccer kicking velocity.In Proceedings of the 4th World Congress of Biomechanics. Calgary, Alberta,Canada: Omnipress.

Anderson, A. F., Dome, D. C., Gautam, S., Awh, M. H. & Rennirt, G. W. (2001).Correlation of anthropometric measurements, strength, anterior cruciate liga-ment size, and intercondylar notch characteristics to sex differences in anteriorcruciate ligament tear rates. American Journal of Sports Medicine, 29(1), 58–66.

Andersson, H., Ekblom, B., & Krustrup, P. (2008). Elite football on artificialturf versus natural grass: Movement patterns, technical standards, and playerimpressions. Journal of Sports Sciences, 26 , 113–122.

Arendt, E. A., Agel, J., & Dick, R. (1999). Anterior cruciate ligament injury patternsamong collegiate men and women. Journal of Athletic Training, 34, 86–92.

Asai, T., Carre, M. J., Akatsuka, T., & Haake, S. J. (2002). The curve kick of a football,I: Impact with the foot. Sports Engineering, 5, 183–192.

Babwah, T. J. (2009). Incidence of football injury during international tournaments.Research in Sports Medicine, 17 , 61–69.

Chen, H., Nigg, B. M., & De Koning, J. (1994). Relationship between plantar pres-sure distribution under the foot and insole comfort. Clinical Biomechanics, 9,335–341.

Dick, R., Putukian, M., Agel, J., Evans, T. A., & Marshall, S. W. (2007). Descriptiveepidemiology of collegiate women’s soccer injuries: National Collegiate AthleticAssociation Injury Surveillance System, 1988–1989 through 2002–2003. Journalof Athletic Training, 42, 278–285.

Eils, E., Streyl, M., Linnenbecker, S., Thorwesten, L., Volker, K., & Rosenbaum,D. (2004). Characteristic plantar pressure distribution patterns during soccer-specific movements. American Journal of Sports Medicine, 32, 140–145.

Ekstrand, J., Hagglund, M., & Fuller, C. W. (2010). Comparison of injuries sus-tained on artificial turf and grass by male and female elite football players.Scandinavian Journal of Medicine & Science in Sports, April, 1–9.

Dow

nloa

ded

by [

Kni

hovn

a C

erge

-Ei]

at 0

3:37

11

Nov

embe

r 20

15

200 E. M. Hennig

Ekstrand, J., Timpka, T., & Hagglund, M. (2006). Risk of injury in elite footballplayed on artificial turf versus natural grass: A prospective two-cohort study.British Journal of Sports Medicine, 40, 975–980.

Fong, D. T., Hong, Y., Chan, L. K., Yung, P. S., & Chan, K. M. (2007). A systematicreview on ankle injury and ankle sprain in sports. Sports Medicine, 37 , 73–94.

Hagen, M., Hoemme, A. K., Umlauf, T., & Hennig, E. M. (2010). Effects of differ-ent shoe-lacing patterns on dorsal pressure distribution during running andperceived comfort. Research in Sports Medicine, 18, 176–187.

Hennig, E. M. (2006). Biomechanische Methoden zur Evaluation und Optimierungvon Fußballschuhen. Orthopädie Schuhtechnik, 2006 , 20–24.

Hennig, E. M. Althoff, K., & Hoemme, A.-K. (2009). Soccer footwear and ball kickingaccuracy. Footwear Science, 1(1, supplement 1), 85–87.

Jordan, C., & Bartlett, R. (1995). Pressure distribution and perceived comfort incasual footwear. Gait & Posture, 3, 215–220.

Krauss, I., Valiant, G., Horstmann, T., & Grau, S. (2010). Comparison of female footmorphology and last design in athletic footwear—Are men’s lasts appropriatefor women? Research in Sports Medicine, 18, 140–156.

Kunz, M. (2007). Big count—265 million playing football. FIFA Magazine, July,10–15.

Lees, A., Asai, T., Andersen, T. B., Nunome, H., & Sterzing, T. (2010) Thebiomechanics of kicking in soccer: A review. Journal of Sports Sciences, 28,805–817.

Milani, T. L., Hennig, E. M., & Lafortune, M. A. (1997). Perceptual and biomechan-ical variables for running in identical shoe constructions with varying midsolehardness. Clinical Biomechanics (Bristol, Avon), 12, 294–300.

Mueller, C., Sterzing, T., Lange, J., & Milani, T. L. (2010). Comprehensive evaluationof player-surface interaction on artificial soccer turf. Sports Biomechanics, 9,193–205.

Nihal, A., Trepman, E., & Nag, D. (2009). First ray disorders in athletes. SportsMedicine and Arthroscopy Review, 17 , 160–166.

Nunome, H., Lake, M., Georgakis, A., & Stergioulas, L. K. (2006). Impact phasekinematics of instep kicking in soccer. Journal of Sports Sciences, 24, 11–22.

Plagenhoef, S. (1971). Patterns of human motion—A cinematographic analysis.Englewood Cliffs, NJ: Prentice Hall.

Shephard, R. J. (1999). Biology and medicine of soccer: An update. Journal of SportsSciences, 17 , 757–786.

Shinkai, H., Nunome, H., Isokawa, M., & Ikegami, Y. (2009). Ball impact dynamicsof instep soccer kicking. Medicine & Science in Sports & Exercise, 41, 889–897.

Shorten, M. R., Hudson, B., & Himmelsbach, J. A. (2003). Shoe-surface traction ofconventional and infilled synthetic turf football surfaces. In P. Milburn, B. D.Wilson, & T. Yanai (Eds.), XIX International Congress of Biomechanics (pp.6–11). Dunedin/New Zealand: University of Otago.

Sterzing, T., & Hennig, E. M. (2008). The influence of soccer shoes on kickingvelocity in full-instep kicks. Exercise and Sport Sciences Reviews, 36 , 91–97.

Sterzing, T., Kroiher, J., & Hennig, E. M. (2009b). Kicking velocity: Barefoot kickingsuperior to shod kicking? In T. Reilly & F. Korkusuz (Eds.), Science and footballVI: The Proceedings of the Sixth World Congress on Science and Football (pp.50–56). New York, NY: Routledge.

Dow

nloa

ded

by [

Kni

hovn

a C

erge

-Ei]

at 0

3:37

11

Nov

embe

r 20

15

Influence of Soccer Shoe Design on Performance and Injuries 201

Sterzing, T., Müller, C., Hennig, E. M., & Milani, T. L. (2009a). Actual and per-ceived running performance in soccer shoes: A series of eight studies. FootwearScience, 1, 5–17.

Tsaousidis, N., & Zatsiorsky, V. (1996). Two types of ball-effector interaction andtheir relative contribution to soccer kicking. Human Movement Science, 15,86l–876.

Valiant, G. A. (1988). Ground reaction forces developed on artificial turf. In T. Reilly,A. Lees, K. Davids, & W. J. Murphy (Eds.), Science and football I (pp. 406–415).London, New York: E. & F. N. Spon.

Villwock, M. R., Meyer, E. G., Powell, J. W., Fouty, A. J., & Haut, R. C. (2009).Football playing surface and shoe design affect rotational traction. AmericanJournal of Sports Medicine, 37 , 518–525.

Walden, M., Hagglund, M., & Ekstrand, J. (2005). UEFA Champions League study:A prospective study of injuries in professional football during the 2001-2002season. British Journal of Sports Medicine, 39, 542–546.

Walden, M., Hagglund, M., Werner, J., & Ekstrand, J. (2011). The epidemiology ofanterior cruciate ligament injury in football (soccer): A review of the literaturefrom a gender-related perspective. Knee Surg Sports Traumatol Arthrosc, 19,3–10.

Wong, P. L., Chamari, K., Mao de, W., Wisloff, U., & Hong, Y. (2007). Higher plantarpressure on the medial side in four soccer-related movements. British Journalof Sports Medicine, 41, 93–100.

Yard, E. E., & Comstock, R. D. (2009). Effects of field location, time in competition,and phase of play on injury severity in high school football. Research in SportsMedicine, 17 , 35–49.

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Kni

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