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Hamstring Strains – Prevention and Rehabilitation

Table of Contents

1. Diagnostic Accuracy of Clinical Tests for Assessment Pages 222-231

Of Hamstring Injury

2. Clinical and Morphological Changes Following 2 Pages 284- 299

Rehabilitation Programs for Acute Hamstring Strain

Injuries

3. Preventative Exercise Progression for Hamstring Strain Pages 1-15

284 | may 2013 | volume 43 | number 5 | journal of orthopaedic & sports physical therapy

[ research report ]

Acute hamstring strain injuries are common in sports involving high-speed movements.7,11,14,24,32 Many athletes return to sport at a suboptimal level of performance,32 which may contribute to

high reinjury rates reported to vary from approximately

15%11,12,35,36 to more than 50%.3,21 This has led to speculation that inad-equate rehabilitation and/or a premature re-turn to sport may be to

blame.21,24,31 Determining the type of re-habilitation program that most effectively promotes muscle tissue and functional recovery is essential to minimize the risk of reinjury and to optimize athlete performance.

Neuromuscular control exercises9,23 and eccentric training1,2,7,13,25,28 have been shown to reduce the likelihood of ham-string injury and are advocated by many to be included as part of rehabilitation following an acute strain injury. Eccentric strengthening, in particular, is believed to increase the series compliance of muscle and allow for longer operating lengths,8,26 which may offset the effects of scar tis-sue.27 Alternatively, Sherry and Best30 found significantly lower reinjury rates in athletes who completed a progressive agility and trunk stabilization (PATS) program, compared to those whose reha-bilitation programs focused on isolated hamstring strengthening and stretching. The authors speculated that the inclu-

TT STUDY DESIGN: Randomized, double-blind, parallel-group clinical trial.

TT OBJECTIVES: To assess differences between a progressive agility and trunk stabilization rehabilitation program and a progressive running and eccentric strengthening rehabilitation program in recovery characteristics following an acute ham-string injury, as measured via physical examination and magnetic resonance imaging (MRI).

TT BACKGROUND: Determining the type of reha-bilitation program that most effectively promotes muscle and functional recovery is essential to minimize reinjury risk and to optimize athlete performance.

TT METHODS: Individuals who sustained a recent hamstring strain injury were randomly assigned to 1 of 2 rehabilitation programs: (1) progressive agility and trunk stabilization or (2) progressive running and eccentric strengthening. MRI and physical examinations were conducted before and after completion of rehabilitation.

TT RESULTS: Thirty-one subjects were enrolled, 29 began rehabilitation, and 25 completed rehabilitation. There were few differences in clinical

or morphological outcome measures between re-habilitation groups across time, and reinjury rates were low for both rehabilitation groups after return to sport (4 of 29 subjects had reinjuries). Greater craniocaudal length of injury, as measured on MRI before the start of rehabilitation, was positively correlated with longer return-to-sport time. At the time of return to sport, although all subjects showed a near-complete resolution of pain and return of muscle strength, no subject showed com-plete resolution of injury as assessed on MRI.

TT CONCLUSION: The 2 rehabilitation programs employed in this study yielded similar results with respect to hamstring muscle recovery and function at the time of return to sport. Evidence of continu-ing muscular healing is present after completion of rehabilitation, despite the appearance of normal physical strength and function on clinical examina-tion.

TT LEVEL OF EVIDENCE: Therapy, level 1b–. J Orthop Sports Phys Ther 2013;43(5):284-299. Epub 13 March 2013. doi:10.2519/jospt.2013.4452

TT KEY WORDS: MRI, muscle, return-to-sport criteria

1Department of Bioengineering and Department of Orthopaedic Surgery, Stanford University, Stanford, CA. 2Sports Rehabilitation, University of Wisconsin Health Sports Medicine, Madison, WI. 3Athletics Department, University of Wisconsin-Madison, Madison, WI. 4Department of Radiology, University of Wisconsin-Madison, Madison, WI. 5Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI. 6Department of Orthopedics and Rehabilitation and Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI. The authors certify that they have no affiliations with or financial involvement in any organization or entity with a direct financial interest in the subject matter or materials discussed in the manuscript. This study was approved by the University of Wisconsin Health Sciences Institutional Review Boards. Address correspondence to Dr Marc A. Sherry, University of Wisconsin Sports Medicine Center, 621 Science Drive, Madison, WI 53711. E-mail: [email protected] T Copyright ©2013 Journal of Orthopaedic & Sports Physical Therapy®

AMY SILDER, PhD1 • MARC A. SHERRY, PT, DPT, LAT, CSCS2 • JENNIFER SANFILIPPO, MS, LAT3

MICHAEL J. TUITE, MD4 • SCOTT J. HETZEL, MS5 • BRYAN C. HEIDERSCHEIT, PT, PhD6

Clinical and Morphological Changes Following 2 Rehabilitation Programs for Acute Hamstring Strain Injuries:

A Randomized Clinical Trial

SUPPLEMENTAL VIDEO ONLINE

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journal of orthopaedic & sports physical therapy | volume 43 | number 5 | may 2013 | 285

sion of exercises targeting muscles that control pelvic motion early in the reha-bilitation process might have facilitated recovery from injury and thereby mini-mized reinjury risk. While both the PATS and the eccentric strengthening rehabili-tation programs are promising and may be effective, they have not been directly compared with regard to restoring mus-cle integrity and function.

It is possible that, regardless of the rehabilitation employed, clinical deter-minants of recovery, as measured during physical exam (eg, no pain, full range of motion, and full strength), do not ad-equately represent complete muscle re-covery and readiness to return to sport. Despite meeting clinical clearance, 37% of the athletes in a study by Connell et al,10 as assessed with magnetic resonance imaging (MRI), showed continued evi-dence of muscle healing after returning to sport, suggesting that athletes may be in an injury-susceptible state.4,10,29,31,34 The use of MRI near the time of injury has an established prognostic role in es-timating convalescent period. A greater amount of T2 hyperintensity, reflective of edema, is associated with a longer reha-bilitation time. This correlation has been made using measurements of cranio-caudal (CC) injury length,10,29,34 percent cross-sectional area of injury,10,31 dis-tance of maximum signal intensity from the ischial tuberosity,4 and maximum T2 hyperintensity.10,31 Regardless of the re-habilitation employed, determining the extent of remaining injury on MRI using these same metrics following the com-pletion of a rehabilitation program may yield further insights into the readiness of the athlete to return to sport.

The purpose of this study was to mon-itor clinical and morphological changes during the course of rehabilitation in individuals with acute hamstring strain injuries and to determine if differences in outcomes may exist between the 2 progressive rehabilitation programs. The rehabilitation programs utilized were a modified PATS program30 and a progres-sive running and eccentric strengthen-

ing (PRES) program. We hypothesized that athletes participating in the PATS program would display a greater amount of muscle recovery at the time of return to sport compared to those in the PRES group. We further hypothesized that, re-gardless of the rehabilitation employed, the majority of athletes would display continued signs of healing on MRI after being clinically cleared to return to sport. Further analyses of time needed to return to sport and MRI measurements were performed to more fully characterize the timeline of hamstring muscle recovery following injury.

METHODS

Trial Design and Participants

This was an equal-randomized, double-blind, parallel-group study. Potential subjects were identified

and recruited via physicians, athletic trainers, and physical therapists in Madi-son, WI and the surrounding communi-ties over a 3-year period. To be eligible for enrollment, individuals had to pre-sent with a suspected hamstring injury occurring within the prior 10 days, to be 16 to 50 years of age, and to be involved in sports that require high-speed running (eg, football) a minimum of 3 days per week. All subjects or parents/guardians provided informed consent to participate in this study, according to a protocol ap-proved by the University of Wisconsin Health Sciences Institutional Review Boards. All testing took place at the Uni-versity of Wisconsin Hospital and Clinics.

All enrolled subjects received a physi-cal examination and MRI within 10 days of the injury. Hamstring injury was con-firmed by physical examination conduct-ed by a physical therapist (B.C.H.) and was based on a sudden-onset mechanism and the presence of 2 or more of the fol-lowing: palpable pain along any of the hamstring muscles, posterior thigh pain without radicular symptoms during a passive straight leg raise, weakness with resisted knee flexion, pain with resisted knee flexion, and/or posterior thigh pain

with sports/running. Subjects were ex-cluded from this study if they were iden-tified as having a complete hamstring disruption or avulsion during the initial physical examination or MRI.

RandomizationFollowing the initial physical exami-nation, the treating physical therapist (M.A.S.) used a 4-block, fixed-allocation randomization process to assign sub-jects to 1 of the 2 rehabilitation groups (the PATS or PRES group). This ran-domization process allowed stratifica-tion for age, initial injury or recurrent injury, and mechanism of injury. These variables have previously been shown to affect return-to-sport time and reinjury rates.3,7,15-17 The random allocation se-quence was generated by an independent biostatistician.

InterventionsEach subject completed rehabilita-tion with the same physical therapist (M.A.S.), who was blinded to any infor-mation obtained from the initial physical examination and MRI. Each rehabilita-tion program had 3 treatment phases. In the first phase, ice was applied to the posterior thigh for 20 minutes after com-pleting each rehabilitation session. Sub-jects progressed into phase 2 when they could walk with the same stride length and stance time on the injured and non-injured limbs (visually assessed) and initiate a pain-free isometric hamstring contraction at 90° of knee flexion with a manual muscle testing grade judged to be at least 4/5. Subjects progressed into phase 3 when they could jog forward and backward with the same stride length and stance time on the injured and nonin-jured limbs (visually assessed) and dem-onstrate 5/5 strength on manual muscle testing of the hamstrings in 3 conditions: prone at 90° of knee flexion with the tibia in neutral position, the tibia rotated in-ternally, and the tibia rotated externally.

The PATS group participated in a modified version of the original PATS rehabilitation program.30 The original

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[ research report ]

PATS program was modified from 2 phases to 3 phases, which allowed for more progressive resistance during the trunk stabilization exercises and added a lunge walk that required trunk rotation and pelvic control with the hamstrings in a lengthened position (APPENDIX A). The progressive agility exercises began with movements primarily in the frontal and transverse planes during phase 1 and progressed to agility and trunk stabiliza-tion movements in the transverse and sagittal planes during phase 2. Phase 3 increased the speed and/or resistance of the exercises.

The PRES group performed a rehabil-itation program consisting of progressive running and eccentric strengthening that was modeled after the work of Baquie and Reid6 (APPENDIX B). Phase 1 consisted of a short-stride jog and hamstring iso-metric exercises. Phase 2 incorporated concentric and eccentric strengthening exercises, and phase 3 progressed to intense eccentric strengthening with a power component. Running during phases 2 and 3 consisted of performing a series of sprints with progressive accel-eration/deceleration (APPENDIX C).

Treatment implementation and re-turn-to-sport criteria were the same for both rehabilitation groups. Rehabilita-tion was to be completed 5 days per week at home. Subjects were asked to track their compliance on an exercise log that was submitted at each follow-up visit. Fol-

low-up visits were scheduled according to patient progress and reported symp-toms, and participants were monitored by phone calls or electronic mail every few days. A minimum of 1 weekly clinic visit was required of all subjects to moni-tor exercise technique and to re-evaluate their status. Subjects were allowed to re-turn to sport when they had no palpable tenderness along the posterior thigh, demonstrated subjective readiness (no apprehension) after completing a series of progressive sprints working up to full speed, and scored 5/5 on manual muscle testing of the hamstrings performed on 4 consecutive repetitions in various knee positions. Knee flexion isometric strength testing was performed in prone with the hip in 0° of flexion and the knee flexed at 90° and 15°. Testing was performed with the tibia in neutral, external rotation, and internal rotation for both knee flexion angles. After being cleared to return to sport by the treating physical therapist, all subjects received a final physical exam and MRI. Any subject who incurred a re-injury at any time during rehabilitation or the 6 months following return to sport received a follow-up MRI as soon as pos-sible after the reinjury and, at that point, discontinued study participation.

OutcomesPrimary Outcome Measures The prima-ry outcome measure was return-to-sport time (days), defined as the period from

initial injury to completion of rehabilita-tion. The CC length of injury, as measured on MRI, was also of primary interest and was measured as the total injured area, accounting for the likelihood that more than 1 muscle would show signs of inju-ry.10,31,33 All MRI studies were conducted using a phased-array torso coil in a 1.5-T TwinSpeed scanner (GE Healthcare, Waukesha, WI). T2-weighted axial and coronal images were obtained using the following scan parameters: TR/TEeff, 2200 to 3200 divided by 70 to 88 milli-seconds; matrix, 512 × 512; 1 NEX; 5-mm axial with no gap; and 4.0/0.4-mm coro-nal. Images were interpreted by the same musculoskeletal radiologist (M.J.T.), who was unaware of rehabilitation group al-location or clinical details other than sus-pected hamstring injury. Each image set was examined separately to help ensure unbiased measurements.Secondary Outcome Measures Medio-lateral width and anterior/posterior depth of the total injured area were also measured on MRI. The cross-sectional area (0.25 × π × mediolateral × anterior/posterior) of the injury, as a percentage of the total cross-sectional area, was cal-culated at the level where the injury had the largest absolute cross-sectional distri-bution in the muscle(s) (FIGURE 1).5,10,29,31,34 In addition, the axial slice on the initial examination with the brightest signal in-tensity was used to measure maximum T2 hyperintensity. On the final MRI, T2 hy-perintensity was measured at the corre-sponding anatomical location. To account for variations in signal quality between examinations, these values were normal-ized to the average signal intensity in normal, uninjured muscle tissue at their respective time points. Finally, the site of injury was categorized as having occurred to the biceps femoris, semimembranosus, or semitendinosus, as well as having oc-curred in either the tendon or the proxi-mal, middle, or distal musculotendon junction. Note that no subject in this study experienced an injury to the distal aspect of any of the hamstring muscles.

Both physical examinations were

FIGURE 1. The percent cross-sectional area of injured muscle was estimated by considering all muscles that exhibited T2 hyperintensity.

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conducted by the same physical thera-pist (B.C.H.), who was unaware of the type of rehabilitation employed or any information obtained from MRI. The subjects’ use of ice and nonsteroidal an-ti-inflammatory drugs (NSAIDs) prior to enrollment was noted, and all sub-jects were asked to refrain from NSAIDs once enrolled. The physical examination included bilateral measures of range of motion, strength, and both location and distribution (length) of pain. Surface pal-pation was used to determine the loca-tion of maximal tenderness, which was measured (cm) relative to the ischial tuberosity. The total CC length (cm) of pain in the muscle/tendon unit was also measured with palpation. The passive straight leg raise was performed with the knee in full extension, whereas ac-tive and passive knee extension was per-formed with the hip in 90° of flexion, and joint angles were recorded at the instant of initial hamstring discomfort/pain on the injured side. Isometric knee flexion strength was measured with the subject prone and the knee flexed to 90° and 15°. When the knee was flexed to 90°, knee flexion strength was also measured with the lower leg in neutral, internal rota-tion, and external rotation. Isometric hip extension strength was measured with the knee at 0° and 90° of flexion. Pain provocation was noted for all strength tests, with strength recorded using a standard manual muscle testing grading scale. As part of the physical examina-tion performed at the time of return to sport, subjects were asked (yes/no) if they (1) were back to their preinjury level of performance, and, if not, whether the hamstring injury was a limiting factor, (2) had any remaining symptoms, and (3) felt hamstring symptoms during running.

After returning to sport, reinjury oc-currence was monitored by phone calls or electronic mail at 2 weeks and at 3, 6, 9, and 12 months. A subject was considered to have a reinjury if there was a specific mechanism that caused a return of pos-terior thigh pain, pain with resisted knee flexion, tenderness to palpation along the

muscle/tendon unit, and decreased abil-ity to do sporting activities (perceived strength and power).

Statistical AnalysisA priori sample-size calculation, based on time to return to sport, was performed

under the assumption that the standard deviation of time to return to sport would be equal to the difference in time to re-turn to sport between the 2 rehabilitation programs. To achieve 80% power for a t test under these assumptions, it was nec-essary to include 17 subjects per group.

Enrolled participants, n = 31

Randomized, n = 29

Excluded, n = 2:• Complete avulsion, n = 1• Lumbosacral pathology with referred thigh pain, n = 1

Allocated to the progressive agility and trunk stabilization (PATS) rehabilitation group, n = 16

Completed rehabilitation, n = 13 Completed rehabilitation, n = 12

Completed return-to-sport testing, n = 13

Completed return-to-sport testing, n = 11

Hamstring reinjury, n = 1Hamstring reinjury, n = 1Dropped out of study, n = 2

Hamstring reinjury the same day as being cleared to return to sport, but prior to return-to-sport testing, n = 1

Anterior cruciate ligament tear, n = 1Hamstring reinjury, n = 1

Allocated to the progressive running and eccentric strengthening rehabilitation group, n = 13

Completed periodic follow-up phone or electronic correspondence through 12 months after injury, n = 13

Completed periodic follow-up phone or electronic correspondence through 12 months after injury, n = 9

FIGURE 2. Flow diagram outlining enrollment and testing procedures.

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[ research report ]All data were analyzed based on inten-

tion to treat. Missing data were treated as missing at random. Subjects who sus-tained a reinjury were documented, and reinjury rates were compared between groups. The data of subjects who sus-tained a reinjury were included in the analysis up to the time of reinjury and considered as missing after the reinjury, so as not to skew their rehabilitation results. This method should not have greatly affected the results, because re-injury rates were uncommon and similar between the groups.

Analysis of subject baseline character-istics between the 2 randomly assigned rehabilitation groups was conducted us-ing t tests or Wilcoxon rank-sum tests for nonnormally distributed data and the Fisher exact test for categorical character-istics. Analysis of time to return to sport was performed with a 2-sample t test. Analyses of change in variables over time were examined with repeated-measures analyses of variance, with time, interven-tion group, and their interaction as fixed effects and subject as a random effect. The repeated-measures analyses of vari-ance were used to estimate the mean and 95% confidence interval (CI) at each of the time points. Analyses of the associa-tion of categorical outcomes and program assignment were conducted with Fisher exact tests. The correlation between time to return to sport and CC length of injury per MRI measure was calculated with a Pearson correlation coefficient. All tests were 2 sided, and significance was set at α = .05.

RESULTS

Of the 31 subjects enrolled, 1 subject was excluded because of a biceps femoris avulsion identified

on initial MRI, and 1 subject was ex-cluded due to sacroiliac pathology with referred posterior thigh pain (FIGURE 2). Twenty-nine subjects began rehabilita-tion. Two of those subjects dropped out of the study without reinjury prior to completion of rehabilitation. In addition,

2 subjects sustained a reinjury during the course of rehabilitation. One reinjury oc-curred during the sprinting portion of return-to-sport testing (subject 26, PRES group). The other reinjury occurred dur-ing phase 3 of the PATS program, while performing a single-leg chair bridge (sub-ject 27). A total of 25 subjects completed rehabilitation; however, only 24 subjects (19 male, 5 female; mean SD age, 24 9 years; height, 1.80 0.09 m; weight, 79 15 kg) completed return-to-sport testing, because subject 3 sustained a re-injury on the same day he was cleared to return to sport but prior to his scheduled return-to-sport testing.

Initial MRIThe time of initial MRI relative to the time of injury occurred later in the PRES group, with a median (interquartile range [IQR]) of 7 (6-7) days after injury, com-pared to 5 (3-6) days in the PATS group (P = .041). With respect to which muscles were determined as being injured, the MRI and physical examinations agreed in all but 9 of the 29 initial cases; 3 sub-jects showed no abnormal T2 intensity on initial MRI, and 6 showed disagreement between the clinical and MRI diagnoses as to the primary muscle injured (TABLE 1).

The following results consider only the 26 subjects with MRI indication of injury (T2 hyperintensity). Injury was isolated to only 1 muscle in 12 subjects, visible in 2 muscles for 10 subjects, visible in 3 muscles for 3 subjects, and visible as T2 hyperintensity in 4 muscles for 1 sub-ject (group difference, P = .180) (TABLE 1). The median (IQR) initial percent cross-sectional area injured, when considering all muscles involved, was 63% (36%-79%) in the PATS group and 61% (48%-91%) in the PRES group (P = .233), and the mean SD maximum T2 signal in-tensity was 3.1 1.0 times that of the un-injured muscle in the PATS group and 2.8 0.7 times that of the uninjured muscle in the PRES group (P = .518) (TABLE 2). No significant differences between rehabili-tation groups were found for any of the initial MRI measurements.

Initial Physical ExaminationThe initial physical examination occurred a median (IQR) of 4 (3-6) days after in-jury in the PATS group and 6 (4-7) days after injury in the PRES group (P = .161). Subject questioning revealed that 17 of the 29 subjects (9 of 16 in the PATS group and 8 of 13 in the PRES group) took NSAIDs within 1 to 3 days after the injury and that 7 subjects (3 in the PATS group) continued NSAID use until en-rollment in this study. All of the subjects reported using ice within 1 to 3 days af-ter injury, and 18 (8 in the PATS group) continued icing through enrollment in this study. The median (IQR) distance of maximum pain during palpation was 7.4 cm (0.0-16.1) distal to the ischial tuber-osity in the PATS group and 7.1 cm (5.5-9.3) in the PRES group (P = .961). The mean SD length of pain with palpation was 9.9 5.2 cm and 8.3 3.0 cm in the PATS and PRES groups, respectively (P = .507). Manual strength testing re-vealed that not all of the subjects exhibit-ed strength deficits on their injured limb during all tests; however, every subject showed a strength deficit during at least 1 strength test (TABLE 3). Range-of-motion tests revealed that some of the subjects exhibited greater range of motion in their injured limb compared to the uninjured limb. No significant differences between rehabilitation groups were found for any of the initial physical examination measurements.

Primary Outcome MeasuresThe mean SD time to return to sport was 28.8 11.4 days in the PRES reha-bilitation group and 25.2 6.3 days in the PATS rehabilitation group (P = .346). The mean CC length of injury from the initial MRI examination was 12.8 cm (95% CI: 7.7, 18.0) in the PATS group and 17.3 cm (95% CI: 9.8, 24.7) in the PRES group (P = .229). Initial CC length of injury was significantly associated with a longer return-to-sport time (r = 0.41, P = .040). At return to sport, CC length in the PRES group was 15.9 cm (95% CI: 8.4, 23.4) compared to 7.9 cm (95% CI:

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2.7, 13.1) in the PRES group (P = .037). The subjects in the PRES group also dis-played less improvement in injury length, with an average improvement from base-line of 1.4 cm (95% CI: –1.9, 4.7) com-

pared to 5.0 cm (95% CI: 2.7, 7.2) for those in the PATS group (P = .035). Ede-ma and hemorrhage can extend into the fascial plane, which can lengthen the CC extent of injury over time (FIGURE 3). As

a result, the change in CC injury length over the course of rehabilitation was vari-able among all subjects, ranging from a 137% increase in length (subject 22) to a 100% decrease in length. The mean

TABLE 1 Subject Characteristics*

Abbreviations: BF, biceps femoris; MRI, magnetic resonance imaging; MTJ, musculotendon junction; NA, not applicable; PATS, progressive agility and trunk stabilization; PRES, progressive running and eccentric strengthening; Prox, proximal; SM, semimembranosus; ST, semitendinosus.*Subjects are numbered and sorted based on return-to-sport time (number of days from injury until being cleared to return to sport). Sixteen subjects par-ticipated in the PATS program and 13 subjects participated in the PRES program. MRI was used to determine the number of muscles involved in the injury, the primary muscle injured, the primary location of injury, and the distance of injury from the ischial tuberosity (distance of maximum T2 hyperintensity). Compliance of home rehabilitation was calculated as the ratio of completed home rehabilitation days (per self-report exercise log) divided by the number of days assigned. NA represents no MRI indication of injury (ie, no T2 hyperintensity). No subject in this study experienced an injury to the distal aspect of the muscle; therefore, all injury locations are relative to the proximal aspect of the muscle.†With respect to the muscle injured, the physical examination diagnosis and MRI disagreed in 9 subjects. No T2 hyperintensity was present in the initial MRI examination of 3 subjects. The muscles injured, as determined from the initial physical examination, in these subjects were as follows: subject 13, ST and SM; subject 18, common insertion; subject 24, ST and SM. The muscles injured, as determined on the initial physical examination, for the remaining 6 subjects were as follows: subject 1, ST and SM; subject 3, ST; subject 4, BF; subject 6, SM; subject 11, BF; subject 17, ST.

Program/Subject Gender, Age Method of InjuryMuscles

Involved, nPrimary Muscle Primary Location

Distance From Origin, cm

Return to Sport, d

Clinic Visits, n

Rehabilitation Compliance (Completed/Assigned), d

PATS

4 Female, 16 y Sprinting 2 SM† Tendon 0.0 37 6 29/34

5 Male, 21 y Sprinting 1 BF Tendon 19.0 34 6 19/30

6 Male, 43 y Sprinting 1 BF† Mid-MTJ 12.4 33 4 20/27

11 Male, 18 y Sprinting 2 ST† Prox MTJ 0.0 28 5 12/13

12 Male, 25 y Sprinting 2 BF Prox MTJ 6.3 27 4 12/21

13 Female, 20 y Extreme stretch 0 NA† NA NA 23 4 13/17

14 Female, 18 y Cutting maneuver 1 SM Prox MTJ 21.2 23 5 16/20


16 Male, 40 y Sprinting 3 BF Mid-MTJ 12.6 23 4 18/20

18 Male, 20 y Sprinting 0 NA† NA NA 21 3 16/19

20 Male, 16 y Sprinting 2 ST Prox MTJ 8.5 20 3 12/12

23 Male, 21 y Extreme stretch 1 BF Distal MTJ 21.1 18 3 10/13

24 Female, 19 y Extreme stretch 0 NA† NA NA 17 3 12/13

27 Male, 36 y Sprinting 3 BF Mid-MTJ 5.2 Reinjury Reinjury NA

28 Male, 18 y Extreme stretch 2 BF Tendon 18.1 Dropout Dropout NA

29 Female, 30 y Sprinting 3 BF Tendon 0.0 Dropout Dropout NA

PRES

1 Male, 44 y Sprinting 2 BF† Prox MTJ 3.7 49 6 36/42

2 Male, 27 y Sprinting 4 BF Everywhere 4.4 47 7 35/40

3 Male, 17 y Sprinting 1 BF† Mid-MTJ 7.2 40 7 32/40





17 Male, 17 y Sprinting 1 BF† Prox MTJ 0.0 23 4 12/13



22 Male, 21 y Extreme stretch 1 SM Prox MTJ 5.5 19 2 11/13

25 Female, 22 y Cutting maneuver 1 SM Mid-MTJ 15.7 13 2 13/13

26 Male, 19 y Sprinting 2 BF Mid-MTJ 7.1 Reinjury Reinjury NA

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[ research report ]

SD improvement of only those subjects with MRI indication of injury who com-pleted all rehabilitation and testing (24 subjects) was 39% 35% (TABLE 2).

Secondary Outcome MeasuresRehabilitation The median (IQR) num-ber of days until return to sport was 23 (21-28) and 28 (20-33) in the PATS and PRES groups, respectively (P = .512). The

median (IQR) number of clinic visits was 4 (3-5) in both groups, and subjects com-pleted a median (IQR) of 20 (13-21) days of rehabilitation at home in the PATS group and 21 (13-28) days in the PRES group (P = .577). Based on self-reported exercise logs, rehabilitation compliance was slightly but not significantly higher in the PRES group (mean SD, 88% 9%) than in the PATS group (80%

12%, P = .070). No significant differences in return-to-sport time, clinic visits, or rehabilitation compliance were noted between rehabilitation groups.Final MRI No subject showed complete injury resolution (no T2 hyperintensity) after being cleared to return to sport (TABLE 2). The mean percent cross-sec-tional area injured, when considering all muscles involved, was 45.0% (95% CI:

TABLE 2Summary of MRI Measures Conducted Before

and After Completion of Rehabilitation*

Abbreviations: MRI, magnetic resonance imaging; NA, not applicable; PATS, progressive agility and trunk stabilization; PRES, progressive running and eccentric strengthening.*MRI was used to determine the craniocaudal length of injury, percent cross-sectional area, and normalized maximum T2 hyperintensity after injury and after completion of rehabilitation. Because more than 1 muscle is often injured,10,31,33 craniocaudal length and percent cross-sectional area were measured with respect to the total injured area. NA represents no magnetic resonance imaging indication of injury (no T2 hyperintensity).

Program/Subject Initial Final Initial Final Initial Final

PATS

4 3.2 0.0 100 0 1.5 1.2

5 9.3 7.3 25 37 1.9 1.6

6 18.8 5.5 79 1 2.5 1.7

11 23.7 22.8 71 55 4.6 3.4

12 17.1 6.9 20 2 3.3 2.0

13 NA NA NA NA NA NA

14 7.7 2.5 47 6 3.4 2.0

15 16.6 6.8 36 14 3.5 2.2

16 25.2 23.5 79 55 3.5 2.9


20 12.8 3.6 33 12 4.2 1.4

23 12.2 4.8 40 43 2.6 2.5


27 33.1 Reinjury 100 Reinjury 1.5 Reinjury

28 19.3 Dropout 86 Dropout 3.3 Dropout

29 13.6 Dropout 100 Dropout 4.1 Dropout

PRES

1 15.6 11.4 64 22 2.4 2.1

2 35.5 28.6 48 28 2.9 3.3


7 30.4 27.8 55 16 2.1 2.1

8 23.5 23.1 61 33 1.8 1.5

9 15.5 12.5 100 40 3.0 2.6

10 8.7 8.6 35 13 3.4 2.5

17 24.1 22.8 91 100 2.8 2.4

19 7.9 10.4 16 30 3.0 2.8

21 13.1 14.6 100 25 2.4 1.6

22 5.2 12.3 70 43 4.6 2.2

25 8.7 2.3 9 2 2.1 1.9


Normalized Maximum T2 HyperintensityCross-sectional Area, %Craniocaudal Length, cm

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28.9%, 61.1%) at baseline in the PATS group and 61.9% (95% CI: 38.8%, 85.1%) at baseline in the PRES group (P = .145). The PATS group improved to a remaining mean percent cross-sectional injured area of 19.2% (95% CI: 2.6%, 35.8%) at follow-up, compared to 33.3% (95% CI: 9.0%, 57.7%) in the PRES group (P = .244). The mean improvement from baseline in percent cross-sectional area injured was 25.8% (95% CI: 8.3%, 43.3%) in the PATS group, compared to 28.6% (95%

CI: 9.8%, 47.4%) in the PRES group (P = .822). The mean normalized T2 signal intensity decreased from baseline slightly more in the PATS group (–0.75; 95% CI: –1.2, –0.31) compared to the PRES group (–0.50; 95% CI: –0.98, –0.03), but this difference was not significant (P = .438). Finally, the presence of early scar tissue formation was apparent in many of the subjects (FIGURES 3 and 4).Final Physical Examination Eleven sub-jects (7 of 13 remaining subjects in the

PATS group and 4 of 12 remaining sub-jects in the PRES group) indicated that they felt remaining hamstring symptoms (eg, pain, tightness) after being cleared to return to sport (P = .444). Twelve subjects (7 in the PATS group and 5 in the PRES group) indicated that they did not feel that they had returned to their preinjury level of performance (P = 1.0). However, only 3 subjects (2 in the PATS group and 1 in the PRES group) reported that their hamstring injury was a limit-

TABLE 3Summary of Physical Examination Results Conducted

Before and After Completion of Rehabilitation*

Abbreviations: ER, external rotation; IR, internal rotation; PATS, progressive agility and trunk stabilization; PRES, progressive running and eccentric strengthening.*Two of the original 29 subjects dropped out of the study and 2 subjects sustained a reinjury prior to completion of rehabilitation.†At initial evaluation, n = 16; at final evaluation, n = 13.‡At initial evaluation, n = 13; at final evaluation, n = 11.§Values are median (range of scores reported), with a 5-point maximum. Isometric strength tests were done using a standard manual muscle testing grading scale. For each strength test, the number of subjects who reported pain in their injured limb is indicated.║Values are mean SD.

Noninjured Injured Reported Pain, n Noninjured Injured Reported Pain, n

Initial evaluation

Hip extension strength§

Knee flexed 5 (4– to 5) 4 (2 to 5) 7 5 (4+ to 5) 4+ (3 to 5) 5

Knee extended 5 (4+ to 5) 4 (2 to 5) 9 5 (4+ to 5) 4 (3 to 5) 8

Knee flexion strength§

Knee flexed to 15° 5 (5) 4– (3 to 4+) 10 5 (5) 4– (3+ to 5) 11

Knee flexed to 90° 5 (5) 4 (3+ to 4+) 10 5 (5) 4 (4– to 5) 10

Knee flexed to 90° with IR 5 (5) 4 (3 to 5) 8 5 (5) 4 (3 to 5) 7

Knee flexed to 90° with ER 5 (5) 4 (4– to 5) 5 5 (5) 4 (3+ to 5) 7

Straight leg raise, deg║ 81 14 63 18 … 80 15 70 16 …

Active knee extension, deg║ 23 10 21 21 … 29 12 26 9 …

Passive knee extension, deg║ 34 17 34 20 … 39 22 35 21 …

Length of pain with palpation, cm║ 0.0 9.9 5.2 … 0.0 8.3 3.0 …

Final evaluation

Hip extension strength§

Knee flexed 5 (4+ to 5) 5 (4+ to 5) 0 5 (5) 5 (4+ to 5) 1

Knee extended 5 (4+ to 5) 5 (4+ to 5) 0 5 (5) 5 (4+ to 5) 0

Knee flexion strength§

Knee flexed to 15° 5 (5) 5 (4 to 5) 1 5 (5) 5 (5) 0

Knee flexed to 90° 5 (5) 5 (4+ to 5) 0 5 (5) 5 (4+ to 5) 1

Knee flexed to 90° with IR 5 (5) 5 (4 to 5) 1 5 (5) 5 (4+ to 5) 1

Knee flexed to 90° with ER 5 (5) 5 (5) 0 5 (5) 5 (5) 0

Straight leg raise, deg║ 86 14 83 13 … 78 13 80 13 …

Active knee extension, deg║ 18 8 18 10 … 26 12 23 11 …

Passive knee extension, deg║ 13 9 13 9 … 21 11 18 9 …

Length of pain with palpation, cm║ 0.0 0.0 … 0.0 0.0 …

PATS† PRES‡

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[ research report ]

ing factor in their performance, and gen-eral deconditioning was the most cited limiting factor. Pain with palpation and during manual strength tests was nearly absent for all subjects at the time of re-turn to sport (TABLE 3). The subjects in the PRES group showed greater range of motion during the straight leg raise in the noninjured limb at the final physical exam, as opposed to those in the PATS group, who exhibited greater range of motion in the injured limb. Additionally, the subjects in the PRES group tended to show greater mean side-to-side differ-ence in the straight leg raise (noninjured limb – injured limb) at the final physical examination (3.4°; 95% CI: –4.0°, 10.7°) compared to those in the PATS group (–1.8°; 95% CI: –9.7°, 6.2°), but that dif-ference was not significant (P = .337). This trend in the magnitude of the side-to-side difference between groups was

consistent with the findings at baseline, where the side-to-side difference was 18.6° (95% CI: 11.6°, 25.7°) for the PATS group and 9.4° (95% CI: 2.0°, 16.7°) for the PRES group (P = .074). No signifi-cant differences between rehabilitation groups were observed during the final physical examination or in the amount of improvement between the initial and final physical examinations.

Symptoms and Reinjury Through 12 MonthsTwo of the 4 subjects who reinjured themselves did so between comple-tion of rehabilitation and the follow-ing 12-month period. Subject 3 (PRES group) sustained a reinjury on the same day as being cleared to return to sport, and subject 17 (PRES group) sustained a reinjury 4 days after completion of rehabilitation. At 2 weeks following re-

turn to sport, only 5 subjects (1 in the PATS group and 4 in the PRES group) reported continued symptoms that lim-ited their normal participation in sport. At approximately 6 weeks after return to sport, subject 10 (PRES group) ruptured the anterior cruciate ligament in the con-tralateral knee while landing from a jump while playing basketball, thereby limiting participation in sport. At 3, 6, 9, and 12 months following return to sport, any-where between 2 and 5 subjects reported continuing symptoms.

MRI of ReinjuryOf the 4 subjects who sustained a rein-jury, only 3 received additional MRI. Re-injuries for those 3 subjects occurred in generally the same location as the initial injury, and injury severity did not ap-pear worse than the initial injury (FIGURE

4). To help establish whether any MRI measurement could be a predictor of re-injury, post hoc analysis was conducted to compare the extent of muscle dam-age measured on initial MRI between the 4 subjects who were reinjured and the other 25 subjects. The reinjured sub-jects had a significantly greater percent area injured on initial MRI (4 reinjured subjects, 87% [95% CI: 68%, 100%]; the remaining 25 subjects, 54% [95% CI: 43%, 65%]; P = .015). CC length and normalized T2 hyperintensity were not significantly different between the 4 sub-jects who reinjured themselves and the remainder of subjects.

DISCUSSION

The purpose of this study was to compare clinical and morphologi-cal recovery characteristics between

2 progressive rehabilitation programs for an acute hamstring strain injury. Despite all subjects achieving a nearly complete resolution of pain and return of isometric muscle strength on physical examination following completion of rehabilitation (TABLE 3), no subjects exhibited complete resolution of injury on MRI (TABLE 2), and early signs of scar tissue formation

FIGURE 3. Coronal and axial T2-weighted MRI scans taken after injury (A and B) and after completion of rehabilitation (C and D). The tendon of the injured limb can initially appear wavy (A; arrow). Scar tissue begins to form during the course of rehabilitation and is clearly visible on MRI scans obtained after completion of rehabilitation (C and D; arrows). Edema and hemorrhage (T2 hyperintensity) can extend into the fascial plane (A and B). Over the course of time, fascial drainage can lengthen the craniocaudal extent of injury and result in MRI measurements longer than the actual muscle/tendon damage. T2 hyperintensity was often more concentrated during the initial MRI examination (A and B), compared to a more diffuse signal present in the follow-up MRI examination (C and D). Abbreviation: MRI, magnetic resonance imaging.

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were apparent for most subjects (FIGURES

3 and 4). Contrary to our first hypothesis, there were few differences between reha-bilitation groups with respect to muscle recovery and function. Most notably, re-turn-to-sport times were similar between groups, and overall reinjury rates were low (1 of 16 subjects in the PATS group and 3 of 13 subjects in the PRES group).

In support of our hypothesis, the presence of injury on MRI was not re-solved when subjects returned to sport. Throughout the course of rehabilitation, the size of injury increased for some subjects in terms of both CC length and cross-sectional area (TABLE 2). Cross-sectional area increased as a result of a more diffuse but larger distribution of T2 hyperintensity. At the time of return to sport, the CC length of injury was longer for the PRES group compared to the PATS group. Nevertheless, few clini-cal conclusions can be drawn from this result, because edema drainage into the fascial plane may occur during the course of rehabilitation and increase the appar-ent CC length of injury and extend the MRI measurements beyond the actual muscle/tendon damage (FIGURE 3). Al-though cross-sectional area and volume of injury are relevant indicators of dam-aged tissue,10,31 our findings suggest that changes in these measures over time may not be good indicators of injury recovery.

Through 1 year after return to sport, only 4 of the 29 subjects had sustained a reinjury, which is a substantially lower rate than that reported by most of the previous studies.3,11,12,21,35,36 Of these 4 re-injuries, 2 occurred during rehabilitation and 2 within the first 2 weeks after return to sport. The median return-to-sport time was 23 days, approximately 1 week longer than other reported times.7,18 Seriousness of participation in sport may affect the commitment of an athlete to complete rehabilitation without undue desire to return to sport too quickly. Specifically, unlike other investigations,3,11,12,35,36 none of the subjects in this study were profes-sional athletes. Further, we utilized 2 of the most supported rehabilitation pro-

grams, which is likely a key factor as to why so few subjects sustained reinjuries. Although we observed very few differenc-es in recovery features between rehabili-tation groups, one potential limitation of the PRES rehabilitation program is that the majority of the rehabilitation exer-cises were only performed on the injured limb. This was done to ensure the stimu-lus was applied to the injured leg and not compensated for by the uninjured leg. We did not observe any clinical strength deficits at return to sport (TABLE 3) or ap-prehension with sports-specific explosive movements, but it is possible that neuro-muscular imbalances exist upon return to sport.

The CC length of injury as measured by MRI at the time of injury has been advocated as a strong predictor of time needed to return to sport.4,10,29,31 Our re-sults support these findings. However, when considering the size of initial injury, past studies have considered only the pri-mary muscle involved when making MRI measurements.4,10,29,31 Because edema and

hemorrhage are often present in more than 1 muscle,10,31,33 we chose to estimate percent cross-sectional area relative to all of the muscles involved in the initial in-jury. We believe that this serves as a more comprehensive assessment of initial in-jury severity.

It is interesting to note that the 2 sub-jects (subjects 2 and 11) who exhibited some of the greatest remaining muscle injury on final MRI were also the 2 sub-jects with the greatest reported pain and strength deficits during the final physi-cal examination. Specifically, the CC lengths of injury for subject 2 (28.6 cm) and subject 11 (22.8 cm) were both sub-stantially longer than the group average (15.3 cm) of those that did not reinjure from both groups. (TABLE 2). This finding supports the idea that edema and hem-orrhage are related to discomfort and loss of strength.19,20 Regardless, 3 sub-jects presented with clinical indication of hamstring strain injury but showed no signs of T2 hyperintensity on their initial or final MRI examinations (TABLE 2). This

FIGURE 4. Coronal and axial T2-weighted magnetic resonance images of subject 3, taken after initial injury (A and B) and 7 days after reinjury (C and D). The location of reinjury was similar to the initial injury. Early signs of scar tissue formation can be seen on the second set of images (C and D; arrows).

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[ research report ]is not uncommon, as it has been found that 18 of 58 athletes enrolled in a previ-ous study29 showed clinical indication of hamstring injury but no sign of injury on MRI; 17 of these 18 athletes were classi-fied as having a grade 1 injury. It is there-fore possible that MRI evidence of injury may not be present for mild, yet painful, hamstring injuries.

Compared to the initial injury, reinju-ries within the same playing season have been shown to occur at the same location and to be more severe on MRI.22 Based on the follow-up MRI measures in sub-jects who had sustained a reinjury in this study, the reinjuries occurred in the same location as the initial injury but were not substantially worse (FIGURE 4). It is un-clear what might have caused the con-trast between these findings across the 2 studies. Post hoc analysis indicated that the percent area injured on initial MRI in the 4 subjects who sustained reinjuries was significantly greater than that in the subjects who were not reinjured. Percent injured area, when including all muscles injured, may be a clinically relevant mea-sure to aid in determining which subjects are most at risk for reinjury; however, further study is needed to investigate the relationship between reinjury rates and percent injured cross-sectional area.

There are several limitations in the present study that prevented direct com-parisons with the literature and statisti-cal conclusions and correlations between the imaging and clinical measurements performed in this study. As some stud-ies have done,30 we used the period from injury to completion of rehabilitation as our definition of return-to-sport time, whereas others have used return to com-petition10,29 or return to preinjury level of performance.4,5 Thus, our return-to-sport time interval (median, 23 days) was considerably less than that of others (median, 112 days).4 A consistent limita-tion between our study and others10,29,34 is the use of MRI at the time of injury. Although MRI measurements may aid the diagnosis and treatment of hamstring strain injuries, it is not feasible for most

recreational athletes to obtain MRI fol-lowing injury. Consistent with common clinical practice, we measured strength using isometric manual muscle testing procedures. Though this measure may be less sensitive than computerized as-sessments involving a dynamometer, we opted to assess isometric strength at multiple joint positions, including short and long lengths of the hamstring mus-cles. Finally, we were unable to enroll 17 subjects in each rehabilitation group, as we initially estimated. However, our rela-tively small subject numbers and diverse athletic population allowed us to present valuable data for clinicians on individual athletes, which highlights how diversity among athletes and injury characteristics may affect recovery during the course of rehabilitation.

CONCLUSION

In general, subjects with an acute hamstring strain injury treated with ei-ther the PATS or PRES rehabilitation

program demonstrated a similar degree of muscle recovery at the time of return to sport. Despite this, there were no sub-jects who exhibited complete resolution of injury on MRI, and 2 of the 4 subjects who reinjured themselves did so within the first 2 weeks after return to sport. It remains to be known how the gradually decreasing presence of injury on MRI af-fects risk of reinjury once athletic activ-ity is resumed. Given the results of this study, it is important that clinicians rec-ognize the presence of ongoing hamstring muscle healing upon completion of a su-pervised rehabilitation program, despite the appearance of normal strength and function on clinical examination. Based on these findings, athletes may benefit from a gradual return to the demands of full sporting activity and from continued independent rehabilitation after return to sport to aid in minimizing reinjury risk. t

KEY POINTSFINDINGS: A modified PATS rehabilita-tion program and a PRES program

produced similar results with respect to muscle recovery and function following a hamstring strain injury. Athletes par-ticipating in both rehabilitation groups continued to show indication of injury on MRI following completion of reha-bilitation, despite meeting clinical clear-ance to return to sport.IMPLICATIONS: The physical therapist should consider that hamstring muscle recovery continues after an athlete meets clinical clearance to return to sport.CAUTION: The relatively small sample size in this study limits any conclusions regarding the effectiveness of either rehabilitation program at minimizing reinjury risk.

ACKNOWLEDGEMENTS: This study was fund-ed by the National Football League Medical Charities, the National Institutes of Health (RR 025011), and the University of Wiscon-sin Sports Medicine Classic Fund. We thank Michael O’Brien and Karolyn Davidson for their help with data analysis.

REFERENCES

1. Arnason A, Andersen TE, Holme I, Engebretsen L, Bahr R. Prevention of hamstring strains in elite soccer: an intervention study. Scand J Med Sci Sports. 2008;18:40-48. http://dx.doi.org/10.1111/j.1600-0838.2006.00634.x

2. Askling C, Karlsson J, Thorstensson A. Hamstring injury occurrence in elite soccer players after preseason strength training with eccentric overload. Scand J Med Sci Sports. 2003;13:244-250.

3. Askling C, Saartok T, Thorstensson A. Type of acute hamstring strain affects flexibility, strength, and time to return to pre-injury level. Br J Sports Med. 2006;40:40-44. http://dx.doi.org/10.1136/bjsm.2005.018879

4. Askling CM, Tengvar M, Saartok T, Thorstensson A. Acute first-time hamstring strains during high-speed running: a longitudinal study includ-ing clinical and magnetic resonance imaging findings. Am J Sports Med. 2007;35:197-206. http://dx.doi.org/10.1177/0363546506294679

5. Askling CM, Tengvar M, Saartok T, Thorstensson A. Acute first-time hamstring strains during slow-speed stretching: clinical, magnetic reso-nance imaging, and recovery characteristics. Am J Sports Med. 2007;35:1716-1724. http://

43-05 Silder.indd 294 4/17/2013 3:49:45 PM


dx.doi.org/10.1177/0363546507303563 6. Baquie P, Reid G. Management of hamstring

pain. Aust Fam Physician. 1999;28:1269-1270. 7. Brooks JH, Fuller CW, Kemp SP, Reddin DB.

Incidence, risk, and prevention of hamstring muscle injuries in professional rugby union. Am J Sports Med. 2006;34:1297-1306. http://dx.doi.org/10.1177/0363546505286022

8. Butterfield TA. Eccentric exercise in vivo: strain-induced muscle damage and adapta-tion in a stable system. Exerc Sport Sci Rev. 2010;38:51-60. http://dx.doi.org/10.1097/JES.0b013e3181d496eb

9. Cameron ML, Adams RD, Maher CG, Misson D. Effect of the HamSprint Drills training pro-gramme on lower limb neuromuscular control in Australian football players. J Sci Med Sport. 2009;12:24-30. http://dx.doi.org/10.1016/j.jsams.2007.09.003

10. Connell DA, Schneider-Kolsky ME, Hoving JL, et al. Longitudinal study comparing sonographic and MRI assessments of acute and healing hamstring injuries. AJR Am J Roentgenol. 2004;183:975-984. http://dx.doi.org/10.2214/ajr.183.4.1830975

11. Ekstrand J, Healy JC, Walden M, Lee JC, English B, Hagglund M. Hamstring muscle injuries in professional football: the correlation of MRI findings with return to play. Br J Sports Med. 2012;46:112-117. http://dx.doi.org/10.1136/bjsports-2011-090155

12. Elliott MC, Zarins B, Powell JW, Kenyon CD. Hamstring muscle strains in profes-sional football players: a 10-year review. Am J Sports Med. 2011;39:843-850. http://dx.doi.org/10.1177/0363546510394647

13. Engebretsen AH, Myklebust G, Holme I, Enge-bretsen L, Bahr R. Prevention of injuries among male soccer players: a prospective, random-ized intervention study targeting players with previous injuries or reduced function. Am J Sports Med. 2008;36:1052-1060. http://dx.doi.org/10.1177/0363546508314432

14. Feeley BT, Kennelly S, Barnes RP, et al. Epi-demiology of National Football League train-ing camp injuries from 1998 to 2007. Am J Sports Med. 2008;36:1597-1603. http://dx.doi.org/10.1177/0363546508316021

15. Gabbe BJ, Bennell KL, Finch CF. Why are older Australian football players at greater risk of hamstring injury? J Sci Med Sport. 2006;9:327-333. http://dx.doi.org/10.1016/j.jsams.2006.01.004

16. Gabbe BJ, Bennell KL, Finch CF, Wajswelner H, Orchard JW. Predictors of hamstring injury at the elite level of Australian football. Scand J Med Sci Sports. 2006;16:7-13. http://dx.doi.

org/10.1111/j.1600-0838.2005.00441.x 17. Gabbe BJ, Finch CF, Bennell KL, Wajswelner H.

Risk factors for hamstring injuries in commu-nity level Australian football. Br J Sports Med. 2005;39:106-110. http://dx.doi.org/10.1136/bjsm.2003.011197

18. Gibbs NJ, Cross TM, Cameron M, Houang MT. The accuracy of MRI in predicting recovery and recurrence of acute grade one hamstring muscle strains within the same season in Aus-tralian Rules football players. J Sci Med Sport. 2004;7:248-258.

19. Holm B, Kristensen MT, Bencke J, Husted H, Kehlet H, Bandholm T. Loss of knee-extension strength is related to knee swelling after total knee arthroplasty. Arch Phys Med Rehabil. 2010;91:1770-1776. http://dx.doi.org/10.1016/j.apmr.2010.07.229

20. Howell JN, Chleboun G, Conatser R. Muscle stiffness, strength loss, swelling and soreness following exercise-induced injury in humans. J Physiol. 1993;464:183-196.

21. Jonhagen S, Nemeth G, Eriksson E. Hamstring injuries in sprinters. The role of concentric and eccentric hamstring muscle strength and flex-ibility. Am J Sports Med. 1994;22:262-266.

22. Koulouris G, Connell DA, Brukner P, Schneider-Kolsky M. Magnetic resonance imaging parameters for assessing risk of recurrent hamstring injuries in elite athletes. Am J Sports Med. 2007;35:1500-1506. http://dx.doi.org/10.1177/0363546507301258

23. Kraemer R, Knobloch K. A soccer-specific bal-ance training program for hamstring muscle and patellar and Achilles tendon injuries: an intervention study in premier league female soccer. Am J Sports Med. 2009;37:1384-1393. http://dx.doi.org/10.1177/0363546509333012

24. Orchard J, Best TM. The management of muscle strain injuries: an early return versus the risk of recurrence. Clin J Sport Med. 2002;12:3-5.

25. Petersen J, Thorborg K, Nielsen MB, Budtz-Jørgensen E, Hölmich P. Preventive effect of eccentric training on acute hamstring injuries in men’s soccer: a cluster-randomized controlled trial. Am J Sports Med. 2011;39:2296-2303. http://dx.doi.org/10.1177/0363546511419277

26. Philippou A, Maridaki M, Bogdanis G, Halapas A, Koutsilieris M. Changes in the mechanical properties of human quadriceps muscle after eccentric exercise. In Vivo. 2009;23:859-865.

27. Proske U, Morgan DL, Brockett CL, Percival P. Identifying athletes at risk of hamstring strains and how to protect them. Clin Exp Pharma-col Physiol. 2004;31:546-550. http://dx.doi.org/10.1111/j.1440-1681.2004.04028.x

28. Schache A. Eccentric hamstring muscle train-

ing can prevent hamstring injuries in soccer players. J Physiother. 2012;58:58. http://dx.doi.org/10.1016/S1836-9553(12)70074-7

29. Schneider-Kolsky ME, Hoving JL, Warren P, Connell DA. A comparison between clinical assessment and magnetic resonance imag-ing of acute hamstring injuries. Am J Sports Med. 2006;34:1008-1015. http://dx.doi.org/10.1177/0363546505283835

30. Sherry MA, Best TM. A comparison of 2 reha-bilitation programs in the treatment of acute hamstring strains. J Orthop Sports Phys Ther. 2004;34:116-125. http://dx.doi.org/10.2519/jospt.2004.1062

31. Slavotinek JP, Verrall GM, Fon GT. Hamstring injury in athletes: using MR imaging measure-ments to compare extent of muscle injury with amount of time lost from competition. AJR Am J Roentgenol. 2002;179:1621-1628. http://dx.doi.org/10.2214/ajr.179.6.1791621

32. Verrall GM, Kalairajah Y, Slavotinek JP, Spriggins AJ. Assessment of player performance following return to sport after hamstring muscle strain injury. J Sci Med Sport. 2006;9:87-90. http://dx.doi.org/10.1016/j.jsams.2006.03.007

33. Verrall GM, Slavotinek JP, Barnes PG, Fon GT. Diagnostic and prognostic value of clinical findings in 83 athletes with posterior thigh injury: comparison of clinical findings with magnetic resonance imaging documentation of hamstring muscle strain. Am J Sports Med. 2003;31:969-973.

34. Verrall GM, Slavotinek JP, Barnes PG, Fon GT, Esterman A. Assessment of physical examina-tion and magnetic resonance imaging findings of hamstring injury as predictors for recurrent injury. J Orthop Sports Phys Ther. 2006;36:215-224. http://dx.doi.org/10.2519/jospt.2006.2086

35. Warren P, Gabbe BJ, Schneider-Kolsky M, Ben-nell KL. Clinical predictors of time to return to competition and of recurrence following hamstring strain in elite Australian footballers. Br J Sports Med. 2010;44:415-419. http://dx.doi.org/10.1136/bjsm.2008.048181

36. Woods C, Hawkins RD, Maltby S, Hulse M, Thomas A, Hodson A. The Football Association Medical Research Programme: an audit of inju-ries in professional football—analysis of ham-string injuries. Br J Sports Med. 2004;38:36-41. http://dx.doi.org/10.1136/bjsm.2002.002352

MOREINFORMATIONWWW.JOSPT.ORG@

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[ research report ]

The progressive agility and trunk stabilization program consisted of 3 phases. The program was designed to last approximately 2 to 6 weeks but progressed on a subject-specific basis, using criteria as indicated. Intensity was used to guide the stationary biking and agility exercises. Descriptions of the intensity levels were given to athletes and assessed qualitatively during the activity. Low intensity was described as little to no exertion; this intensity can be thought of as primarily used to create motion. Moderate intensity was described as that above daily activity, with some perceived exertion. High intensity was described as a perceived exertion near that of competitive sports.

Exercises Sets

Phase 1 Stationary bike• Low intensity

1 × 10 min

10-m back-and-forth sidestep shuffle• Low to moderate intensity• Pain-free speed and stride

5 × 30 s

10-m back-and-forth grapevine• Low to moderate intensity• Pain-free speed and stride

5 × 30 s

Fast foot stepping in place 3 × 30 s

Prone body bridge (forearm plank) 5 × 10 s

Side body bridge (plank) 5 × 10 s on each side

Supine bent-knee bridge 10 × 5 s

Standing single-leg balance• Progressing from eyes open to eyes closed• Lean forward slightly

4 × 20 s for each limb

Phase 2 Stationary bike• Moderate intensity

1 × 10 min

10-m back-and-forth sidestep shuffle• Moderate to high intensity• Pain-free speed and stride

6 × 30 s

10-m back-and-forth grapevine• Moderate to high intensity• Pain-free speed and stride

6 × 30 s

10-m back-and-forth boxer shuffle• Low to moderate intensity• Pain-free speed and stride

4 × 30 s

Rotating body bridge (hand plank)• 5-s hold on each side

2 × 10 repetitions on each side

Supine bent-knee bridge with walk-outs1. Begin with knees very bent2. Holding hips up entire time, alternate small steps out with feet, decreasing

knee flexion

3 × 10 repetitions

Single-leg windmill touches without weight 4 × 8 repetitions per arm per lower limb

Lunge walk with trunk rotation, opposite-hand toe touch, and T lift• Hip flexed such that the chest and back leg are parallel to the ground as the toe

reaches to the opposite foot

2 × 10 steps per limb

Single-leg balance with forward trunk lean and opposite-leg hip extension 5 × 10 s per limb

Phase 3 Stationary bike• Moderate to high intensity

1 × 10 min

APPENDIX A

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Exercises Sets

Phase 3 (continued)

30-m back-and-forth sideshuffle• Moderate to high intensity• Pain-free speed and stride

6 × 30 s

30-m back-and-forth grapevine• Moderate to high intensity• Pain-free speed and stride

6 × 30 s

10-m back-and-forth boxer shuffle• Moderate to high intensity• Pain-free speed and stride

4 × 30 s

Forward/backward accelerations• Pain-free progression from 5 m to 10 m to 20 m

6 × 30 s

Rotating body bridge with dumbbell• 5-s hold on each side• 1.4 to 3.6 kg (3-8 lb) based on individual body weight and ability

2 × 10 repetitions

Supine single-leg chair bridge1. 1 leg on a high chair with hip flexed2. Raise hips, lower, and repeat• Progress from slow to fast speed

3 × 15 repetitions

Single-leg windmill touches with dumbbells• 2.3 to 6.8 kg (5-15 lb) based on individual body weight and ability

4 × 8 repetitions per arm per lower limb

Lunge walk with trunk rotation, opposite-hand toe touch, and T lift• Hip flexed such that the chest and back lower limb are parallel to the ground as the

toe reaches to the opposite foot• 2.3 to 6.8 kg (5-15 lb) based on individual body weight and ability

2 × 10 steps per limb

Symptom-free individual practice of sport, avoiding sprinting and high-speed maneuvers

APPENDIX A

The progressive running and eccentric strengthening program consisted of 3 phases. The program was designed to last approximately 2 to 6 weeks but progressed on a subject-specific basis, using criteria as indicated. Intensity was used to guide the stationary biking and agility exercises. Descriptions of the intensity levels were given to athletes and assessed qualitatively during the activity. Low intensity was described as little to no exertion; this intensity can be thought of as primarily used to create motion. Moderate intensity was described as that above daily activity, with some perceived exertion. High intensity was described as a perceived exertion near that of competitive sports.

Exercises Sets

Phase 1 Stationary bike• Low intensity

1 × 10 min

Increasing-effort hamstring isometrics• Submaximal to maximal

10 × 10 s at 3 knee flexion angles (30°, 60°, 90°)

Bilateral supine heel slides1. Lie supine on slippery surface2. Slide heels to buttock and back out

15 repetitions

Progressive running program (APPENDIX C)

APPENDIX B

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Exercises Sets

Phase 2 Stationary bike• Moderate intensity

1 × 10 min

Prone hamstring curls• Prone with hip flexed at edge of a table (chest and stomach on the table)• Use ankle weights or resistance band

3 × 12 repetitions, injured limb only

Prone hip extension off edge of bed or table through full range of motion (chest and stomach on the table)

• Use ankle weights or resistance band


Prone leg lift and knee curl1. Lift straight leg slightly off floor (extend hip)2. Flex knee without dropping leg


Progressive running program (APPENDIX C)

Phase 3 Stationary bike• Moderate to high intensity

1 × 10 min

Nordic hamstring drop-curl progression• Complete 2 pain-free sessions before progressing to next level• Complete all 3 sessions, drop only, then progress through sessions again with drop

and curl

3 times per week; (1) 2 × 5 to 8 repetitions, drop only; (2) 3 × 5 to 8 repetitions, drop only; (3) 3 × 9 to 12 repetitions, drop only

Prone foot catches with ankle weight1. Lie prone with hip flexed at edge of table2. Lift leg until parallel with table3. Drop leg quickly4. Try to slow the fall and pause just before foot hits the floor

2 × 10 to 20 repetitions, injured limb only

Prone hip extension off the edge of bed or table for full range of motion• Use ankle weight1. Lift leg parallel to the floor2. Drop and catch before leg touches floor

2 × 10 to 20 repetitions, injured limb only

Standing 1-leg foot catches1. Stand against the wall2. Repeat the swing phase of sprinting, pausing just prior to full hip flexion, with the

knee extended


Symptom-free individual practice of sport, avoiding sprinting and high-speed maneuvers

APPENDIX B

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PROGRESSIVE RUNNING SCHEDULEExercises

• 5 min of gentle stretching before and after each session, 3 × 20 s each- Standing calf stretch- Standing quadriceps stretch- Half kneeling hip flexor stretch- Groin or adductor stretch- Standing hamstring stretch

• Repeat each level 3 times, progressing to the next level when pain free• Maximum of 3 levels per session• On the following session, start at the second-highest level completed

• Ice after each session, 20 min

Acceleration Distance, mConstant Speed (Maximum,

75% Speed) Distance, m Deceleration Distance, m

Level 1 40 20 40

Level 2 35 20 35

Level 3 25 20 25

Level 4 20 20 20

Level 5 15 20 15

Level 6 10 20 10

Acceleration Distance, mConstant Speed (Maximum,

95% Speed) Distance, m Deceleration Distance, m

Level 7 40 20 40

Level 8 35 20 35

Level 9 25 20 25

Level 10 20 20 20

Level 11 15 20 15

Level 12 10 20 10

APPENDIX C

VIEW Videos on JOSPT’s Website

Videos posted with select articles on the Journal’s website (www.jospt.org) show how conditions are diagnosed and interventions performed. For a list of available videos, click on “COLLECTIONS” in the navigation bar in the left-hand column of the home page, select “Media”, check “Video”, and click “Browse”. A list of articles with videos will be displayed.

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222 | april 2013 | volume 43 | number 4 | journal of orthopaedic & sports physical therapy

[ research report ]

Hamstring injuries are one of the most common soft tissue injuries in athletes.4,8-10,31,35,44 Treatment and management of hamstring injuries,20,24,25 as well as injury prevention and return to sport,1,4,6,16,30,32 have received significant

research effort in the past 10 years. Examination of athletes with

hamstring injury has tradition-ally relied on combinations of pain with palpation of the in-jured area, traditional manual muscle testing, passive straight leg raise testing,3-6,12,24,41 magnetic

resonance imaging (MRI),4,5,34,38,41 and isokinetic testing.34 However, the studies on diagnostic accuracy of palpation, tra-ditional manual muscle testing, and leg raise testing have not provided sufficient information to quantify the clinical abil-ity of these tests to differentiate between those with and without confirmed ham-string injury. In addition, some of these tests have been described only for assess-ment of readiness for return to sport.2-5

MRI4,5,34,38,41 and ultrasonography (US) are considered the criterion refer-ence standards for diagnosis of ham-string injuries.7,13,38 However, both MRI and US are not practical alternatives for diagnosis of hamstring injury due to the high incidence of this injury and the costs associated with these diagnostic tests. Therefore, clinical tests with strong psychometric properties for use in diag-nosing this condition are needed. The purpose of this study was to conduct a systematic review of the literature report-ing on the diagnostic accuracy of clinical tests that have been proposed to be help-ful in the diagnosis of hamstring injury. The studies included had cohort, case-control, and/or cross-sectional designs

TT STUDY DESIGN: Systematic literature review.

TT BACKGROUND: The diagnosis of a hamstring injury has traditionally relied on various clinical measures (eg, palpation, swelling, manual resis-tance), as well as the use of diagnostic imaging. But a few studies have suggested the use of specific clinical tests that may be helpful for the diagnostic process.

TT OBJECTIVE: To summarize the current literature on the diagnostic accuracy of ortho-paedic special tests for hamstring injuries and to determine their clinical utility.

TT METHODS: A computer-assisted literature search of the MEDLINE, CINAHL, and Embase databases (along with a manual search of grey literature) was conducted using key words related to diagnostic accuracy of hamstring injuries. To be considered for inclusion in the review, the study required (1) patients with hamstring or posterior thigh pain; (2) a cohort, case-control, or cross-sectional design; (3) inclusion of at least 1 clinical examination test used to evaluate hamstring pathology; (4) comparison against an acceptable reference standard; (5) reporting of diagnostic accuracy of the measures (sensitivity [SN], specificity [SP], or likelihood ratios); and (6) publication in English. SN, SP, and positive and negative likelihood ratios were calculated for each diagnostic test.

TT RESULTS: The search strategy identified 602

potential articles, of which only 3 articles met the inclusion criteria, with only 1 of these 3 articles be-ing of high quality. Two of the studies investigated a single special test, whereas the third article exam-ined a composite clinical assessment employing various special tests. The SN values ranged from 0.55 (95% confidence interval [CI]: 0.46, 0.69) for the active range-of-motion test to 1.00 (95% CI: 0.97, 1.00) for the taking-off-the-shoe test. The SP values ranged from 0.03 (95% CI: 0.00, 0.22) for the composite clinical assessment to 1.00 (95% CI: 0.97, 1.00) for the taking-off-the-shoe test, ac-tive range-of-motion test, passive range-of-motion test, and resisted range-of-motion test. The use of a single special test demonstrated stronger SP than SN properties, whereas the composite clinical assessment demonstrated stronger SN than SP properties.

TT CONCLUSION: Very few studies have investi-gated the utilization of clinical special tests for the diagnosis of hamstring injuries. Further studies of higher quality design are suggested prior to advocating independent clinical utilization of these special tests.

TT LEVEL OF EVIDENCE: Diagnosis, level 3b. J Orthop Sports Phys Ther 2013;43(4):222-231. Epub 14 January 2013. doi:10.2519/jospt.2013.4343

TT KEY WORDS: diagnosis, sensitivity, specificity, strain

1Doctor of Physical Therapy Division, Department of Community and Family Medicine, Duke University School of Medicine, Durham, NC. The authors certify that they have no affiliations with or financial involvement in any organization or entity with a direct financial interest in the subject matter or materials discussed in the manuscript. Address correspondence to Dr Michael P. Reiman, Duke University School of Medicine, Duke University Medical Center, Doctor of Physical Therapy Division, DUMC 104002, 2200 West Main Street, Suite B 230, Durham, NC 27705. E-mail: [email protected] T Copyright ©2013 Journal of Orthopaedic & Sports Physical Therapy

MICHAEL P. REIMAN, PT, DPT, OCS, SCS, ATC, FAAOMPT, CSCS1 • JANICE K. LOUDON, PT, PhD, SCS, ATC, CSCS1 • ADAM P. GOODE, PT, DPT, PhD1

Diagnostic Accuracy of Clinical Tests for Assessment of Hamstring Injury:

A Systematic Review

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journal of orthopaedic & sports physical therapy | volume 43 | number 4 | april 2013 | 223

that enabled comparison of the diagnos-tic accuracy of clinical tests to their ap-propriate criterion reference standards.

METHODS

The PRISMA guidelines were uti-lized during the search-and-re-porting phase of this review. The

PRISMA statement includes a 27-item checklist designed to be used as a ba-sis for reporting systematic reviews of randomized trials,33 but can also be applied to multiple forms of research methodologies.40

Search StrategyA systematic, computerized search of the literature in the MEDLINE, CI-NAHL, and Embase databases was conducted in February 2012. The MeSH search string in MEDLINE was (((hamstring[ti] OR semitendinosus[ti] OR semimembranosus[ti] OR “poste-rior thigh”[ti] OR “biceps femoris”[ti])) AND ((strain) OR strained OR (tear) OR tears OR (injury) OR injuries AND “evaluation” OR “physical examination” OR “orthopedic clinical examination” OR diagnosis OR diagnose)) NOT (“cru-ciate ligament”[ti] OR “ACL”[ti] OR “PCL”[ti]), with limits for English lan-guage and humans. Two authors (M.P.R. and J.K.L.) independently performed

the search. Because computerized search results for diagnostic accuracy data fre-quently omit relevant articles,19 the ref-erence lists of all selected publications were checked to retrieve relevant pub-lications that were not identified in the computerized search. The grey litera-ture, which included publications, post-ers, abstracts, or conference proceedings, was hand searched. The reference lists and grey literature were searched by 1 author (M.P.R.). To identify relevant ar-ticles, titles and abstracts of all identified citations were independently screened by both authors. Full-text articles were retrieved if the abstract provided insuf-ficient information to establish eligibility or if the article passed the first eligibility screening.

Selection CriteriaArticles examining clinical tests for ham-string injuries were eligible if they met all of the following criteria: (1) patients presented with hamstring or posterior thigh pain; (2) a cohort, case-control, or cross-sectional design was used; (3) the study included at least 1 clinical ex-amination test to evaluate hamstring pathology; (4) the results of the clinical test were compared against an acceptable reference standard (MRI or US)7,13,38; (5) the study reported diagnostic accuracy of the measures (sensitivity [SN], specificity

[SP], positive likelihood ratio [+LR], and negative likelihood ratio [–LR]); and (6) the study was published in English.

An article was excluded if (1) the re-ported pathology was associated with a condition located elsewhere (eg, lumbar spine) that referred pain to the ham-string/posterior thigh, (2) the study did not provide either SN or SP data, (3) the clinical examination test was performed under any form of anesthesia or on ca-davers, (4) the study used specialized instrumentation not readily available to all clinicians, and (5) the study was per-formed on infants/toddlers.

All criteria were independently ap-plied by both reviewers to the full text of the articles that passed the first eligibil-ity screening. Disagreements among the reviewers were discussed and resolved during a consensus meeting.

Quality AssessmentThe Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool43 was used to determine the quality of the stud-ies. The QUADAS consists of 14 items (TABLE 1), each with response categories of yes, no, or unclear. A yes score indicates sufficient information, with bias consid-ered unlikely; a no score indicates suffi-cient information, but with potential bias from inadequate design or conduct; and an unclear score indicates that the article

TABLE 1 Quality Assessment of the Studies Included in the Review

Abbreviations: N, no; U, unclear; Y, yes.*Item 1: was the spectrum of patients representative of those in clinical practice? Item 2: were selection criteria clearly described? Item 3: is the reference stan-dard likely to classify the target condition correctly? Item 4: is the period of time between the reference standard and index test acceptable? Item 5: did the whole sample of patients receive verification using the reference standard? Item 6: did patients receive the same reference standard regardless of the index test result? Item 7: was the reference standard independent of the index test? Item 8: was the execution of the index test described in sufficient detail for replication? Item 9: was the execution of the reference standard described in sufficient detail for replication? Item 10: were the index test results interpreted without knowledge of the reference standard? Item 11: was the reference standard interpreted without knowledge of the results of the index test? Item 12: were the same clinical criteria available when test results were interpreted as would be in clinical practice? Item 13: were uninterpretable/intermediate test results reported? Item 14: were withdrawals from the study explained?

Article 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Total

Cacchio et al11 N/U Y Y N/U Y Y Y Y Y N/U N/U Y N/U N/U 8

Schneider-Kolsky et al37 Y Y Y Y Y Y Y Y Y Y N/U Y N/U Y 12

Zeren and Oztekin45 N/U N/U Y N/U Y Y Y Y N/U N/U N/U Y N/U N/U 6

Item*

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[ research report ]or methodology provided insufficient information or the methodology was un-clear. The total score was a count of all of the criteria that scored yes (valued as 1, whereas no and unclear scores were val-ued as zero), with a maximum attainable score of 14. The methodological quality of each of the studies was independently as-sessed by both reviewers. Disagreements were discussed and resolved during a consensus meeting. Qualitatively, stud-ies that exhibit higher QUADAS values are associated with less risk of design bias than those with lower values. Similar to previously published reviews, the stud-ies were stratified as “high quality/low risk of bias” if their QUADAS score was 10 or greater or as “low quality/high risk of bias” if their QUADAS score was less than 10.23

Data ExtractionOne author (M.P.R.) independently gathered data regarding study popula-tion, setting, special test performance, pathology, diagnostic reference standard, and number of true positives, false posi-tives, false negatives, and true negatives for calculation of SN, SP, +LR, and –LR when these were not provided. The other authors (J.K.L. and A.P.G.) verified data extraction accuracy once completed. Cell counts of zero are common in diagnostic accuracy studies, and in such instances 0.5 was added to all cells, as suggested by Cox.15 SN is defined as the percentage of people who test positive for a specific disease among a group of people who have the disease. SP is the percentage of people who test negative for a specific disease among a group of people who do not have the diagnosis/disorder. A +LR is the ratio of a positive test result in people with the pathology to a positive test re-sult in people without the pathology. A +LR identifies the strength of a test in determining the presence of a finding, and is calculated by the formula SN/(1 – SP). A –LR is the ratio of a negative test result in people with the pathology to a negative test result in people without the pathology, and is calculated by the for-

mula (1 – SN)/SP. The higher the +LR and the lower the –LR, the greater the posttest probability is altered. Posttest probability can be altered to a minimal degree with +LRs of 1.0 to 2.0 or –LRs of 0.5 to 1.0, to a small degree with +LRs of 2.0 to 5.0 or –LRs of 0.2 to 0.5, to a moderate degree with +LRs of 5.0 to 10.0 and –LRs of 0.1 to 0.2, and to a large and almost conclusive degree with +LRs greater than 10.0 and –LRs less than 0.1. Pretest probability is defined as the probability of the target disorder be-fore a diagnostic test result is known. It represents the probability that a specific patient with a specific past history, pre-senting to a specific clinical setting with a specific symptom complex, has a specific diagnosis.26

RESULTS

Selection of Studies

The systematic search through MEDLINE, CINAHL, and Em-base netted 915 abstracts, and

8 additional papers were identified through an extensive hand search. In total, 602 titles were initially retained after duplicates were removed. Ab-stract and full-text review reduced the acceptable papers to 3 (FIGURE, TABLE 2). The sample sizes of the 3 studies were 46,11 140,45 and 5837 athletes, respec-tively. Cacchio et al11 and Zeren and Oztekin45 investigated individual spe-cial tests, whereas Schneider-Kolsky et al37 employed a composite clinical assessment.

915 abstracts identified through MEDLINE (n = 596), CINAHL (n = 143), and Embase (n = 176)

Identification

Screening

Inclusion

8 abstracts identified through hand search

602 titles included after duplicates removed

576 abstracts rejected because each did not reflect diagnosis

3 studies included in the qualitative analysis

18 articles rejected for providing quantitative numbers that did not allow measurement of sensitivity or specificity

602 titles screened

26 abstracts screened

8 full text articles screened

5 articles rejected for failing to calculate diagnostic accuracy or failing to report both sensitivity and specificity

FIGURE. Flow diagram for study inclusion.

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Quality ScoresThe kappa value between testers for the overall score using the QUADAS was 0.68 (95% confidence interval [CI]: 0.44, 0.91), with this point estimate re-flecting substantial agreement.27 Of the individual items of the QUADAS, items 1, 3, 5, 6, 7, 8, 12, and 14 had 100% agree-ment; and items 2, 4, 9, 10, 11, and 13 had 83% agreement between raters. Quality scores for each of the studies are shown in TABLE 3. Using our previously estab-lished stratification of the QUADAS, the Schneider-Kolsky et al37 article was con-sidered of high quality/low risk of bias, whereas the Cacchio et al11 and the Zeren and Oztekin45 articles had a QUADAS score of less than 10 points, suggesting low quality/high risk of bias (TABLE 3). The most poorly scored items of the QUADAS were items 1 (spectrum representative of those in clinical practice), 4 (time period between reference standard and index test), 10 (index test results interpretation without knowledge of reference stan-dard), 11 (reference standard interpre-

tation without knowledge of index test results), 13 (uninterpretable test results), and 14 (explanation of withdrawals).

Diagnostic Clinical TestsSchneider-Kolsky et al37 and Cacchio et al11 used MRI as the reference standard, whereas Zeren and Oztekin,45 the study with the lowest score on the QUADAS, used diagnostic US. Based on recent ad-vances in technology, diagnostic US is now considered comparable to MRI for the diagnosis of muscle injury.7,13,38 Seven individual special tests were investigated in the Cacchio et al11 and Zeren and Oz-tekin45 studies. Schneider-Kolsky et al37 used a composite method based on the interpretation of 3 special tests (TABLE 3, APPENDIX).

Cacchio et al11 examined the Puranen-Orava, bent-knee stretch, and modified bent-knee stretch tests in 46 symptom-atic and 46 asymptomatic athletes. The interrater reliability of the tests, based on intraclass correlation coefficients, was 0.84 (95% CI: 0.72, 0.87) for the

Puranen-Orava test, 0.86 (95% CI: 0.78, 0.93) for the bent-knee stretch test, and 0.88 (95% CI: 0.82, 0.94) for the modi-fied bent-knee stretch test. The Puranen-Orava test was determined to have an SP of 0.82 (95% CI: 0.68, 0.92) and an SN of 0.76 (95% CI: 0.61, 0.87). The bent-knee stretch test had SN and SP values of 0.84 (95% CI: 0.71, 0.93) and 0.87 (95% CI: 0.73, 0.95), respectively. The modi-fied bent-knee stretch test had SN and SP values of 0.89 (95% CI: 0.76, 0.96) and 0.91 (95% CI: 0.79, 0.97), respectively.

Zeren and Oztekin45 examined 4 in-dividual special tests for proximal ham-string muscle strain injury in 140 male professional soccer players: the taking-off-the-shoe test, active range-of-motion test, passive range-of-motion test, and resisted range-of-motion test. The crite-rion standard utilized by the authors was US. Reliability of the tests was not de-termined in this study. SP for all of these tests was 1.00 (95% CI: 0.97, 1.00). All 140 noninvolved legs (control side) tested negative, resulting in an SP of 1.00 (95% CI: 0.97, 1.00) for all of these tests.45 The SN for these tests ranged from 0.55 (95% CI: 0.46, 0.63) for the active range-of-motion test to 1.00 (95% CI: 0.97, 1.00) for the taking-off-the-shoe test.

Schneider-Kolsky et al37 investigated the diagnostic accuracy of a composite clinical assessment in 58 professional footballers (rugby) with hamstring inju-ries, with a positive test result being the reproduction of the patient’s concordant pain/stiffness during any of the 3 indi-vidual tests. Reliability of the testing was not investigated. The composite clinical assessment had an SN of 0.95 (95% CI: 0.83, 0.99) and an SP of 0.03 (95% CI: 0.00, 0.22).

DISCUSSION

Our study investigated the diag-nostic accuracy of selected ortho-paedic special tests for hamstring

injury. There were only 3 studies illus-trating tests that included both SN and SP values. Our review also found limited

TABLE 2 Summary of Studies Included in the Review

Author/Test Subjects Sport Symptom Duration

Cacchio et al11

• Puranen-Orava test• Bent-knee stretch test• Modified bent-knee

stretch test

46 symptomatic athletes (mean SD age, 22.8 2.3 y; height, 1.79 m; weight, 76.8 11.3 kg; 12 females, 34 males)

46 asymptomatic athletes (mean SD age, 23.2 1.8 y; height, 1.78 m; weight, 75.9 12.6 kg; 11 females, 35 males)

Sprinters, distance runners, long jumpers, hurdlers, soccer and rugby players

15.0 7.2 mo

Zeren and Oztekin45

• Taking-off-the-shoe test

• Active range- of-motion test

• Passive range- of-motion test

• Resisted range- of-motion test

140 professional male soccer players (age range, 17-33 y) with a history and clinical findings of a proximal hamstring muscle strain injury

Soccer Examined between 0 and 42 d from injury

Schneider-Kolsky et al37

• Composite clinical assessment

58 professional footballers who received a diagnosis from the trainer or physician of an acute hamstring injury (mean SD age, 24 3.8 y; height, 186.3 6.0 cm; weight, 87.9 8.7 kg)

Professional footballers playing in the Austra-lian Football League

Examined within 3 d of injury

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[ research report ]

quality of these studies. The diagnostic accuracy of the tests investigated in this study was quite variable, with SN values ranging from 0.55 (95% CI: 0.46, 0.63) to 1.00 (95% CI: 0.97, 1.00) and SP values ranging from 0.03 (95% CI: 0.00, 0.22) to 1.00 (95% CI: 0.97, 1.00). The paucity of studies precluded meta-analysis.

The study by Schneider-Kolsky et al,37 the only investigation that utilized composite clinical testing, had less po-tential for bias (as demonstrated by a higher QUADAS score) than the Cac-chio et al11 and Zeren and Oztekin45 stud-ies. Although this study had the highest quality and least potential for bias of the 3 studies in this review, it had the weak-est ability to determine a diagnosis. Al-though this study had a high SN value of 0.95 (95% CI: 0.83, 0.99), it only altered the posttest probability of a diagnosis to a degree less than minimal, with a +LR of 0.97 and a –LR of 1.9. The subjects in this study were examined more acutely than those in the Cacchio et al11 and Zeren and Oztekin45 studies (within 3 days of onset), and the sample size was moderate com-pared to the other 2 studies.

Sample sizes in the Cacchio et al11 and Schneider-Kolsky et al37 studies were much smaller than that in the Zeren and Oztekin study.45 Although Zeren and

Oztekin45 commendably investigated a fairly large sample of 140 male soccer players (using the noninvolved limb as a control), the study scored the lowest (6/14) of the 3 studies on the QUADAS. Despite the fact that the taking-off-the-shoe test demonstrated 1.00 (95% CI: 0.97, 1.00) SN and SP, as well as the fact that the +LR and –LR values for this test were suggestive of increasing and decreasing, respectively, posttest prob-ability of a hamstring injury diagnosis al-most conclusively, the zero cell counts for false positive and false negative resulted in substantially large CIs for both likeli-hood ratio values. The other tests from this study demonstrated –LR values in the 0.4-to-0.5 range. Pretest-to-posttest probability shifts of ruling out a diagno-sis of hamstring injury for these other tests would, therefore, be small and of questionable clinical utility. In contrast, the QUADAS scores for the Cacchio et al11 and Schneider-Kolsky et al37 studies were higher, potentially resulting in a lower risk of bias. However, the sample sizes and diagnostic accuracy values in these studies were smaller than those in Zeren and Oztekin.45

As previously mentioned, the time frame from injury onset to examina-tion was variable in all 3 studies. The

Schneider-Kolsky et al37 and Zeren and Oztekin45 studies examined the more acutely injured athlete, compared to the Cacchio et al11 study. Therefore, the acuteness of the injury, like the type of injury, as previously discussed, could be a confounding factor in the diagnosis of hamstring injury.

The assessment of posterior thigh pain may be complex on occasion. Once red flags are ruled out (previous history of cancer, age of onset less than 20 or greater than 55 years old, saddle anes-thesia, and so on),17 a detailed subjective history can help rule out signs and symp-toms inconsistent with hamstring injury. Additionally, examination of the lumbar spine, pelvis, and related nervous system may assist in ruling out these areas as potential pain generators. Lumbar spine contribution to posterior thigh–related pain could appropriately be ruled out (SN, 0.92)18 or ruled in (SP, 0.94)28 with repeated motions for potential lumbar spine radiculopathy. Orthopaedic spe-cial tests for this same purpose would include the slump test (SN, 0.83)39 and straight leg raise test (SN, 0.97).42 Sac-roiliac joint dysfunction and piriformis syndrome could be ruled out with clus-ter testing (SN, 0.91)29 and the FAIR test (SN, 0.88-0.97),21 respectively, as

TABLE 3Summary of Studies Reporting on the Diagnostic Accuracy of Orthopaedic Special Tests for Hamstring Pathologies*

Abbreviations: ICC, intraclass correlation coefficient for interrater reliability; –LR, negative likelihood ratio; NR, not reported; +LR, positive likelihood ratio; QUADAS, Quality Assessment of Diagnostic Accuracy Studies; SN, sensitivity; SP, specificity.*Values in parentheses are 95% confidence interval, except for QUADAS.†Diagnostic accuracy calculations reported by authors of this systematic review.

Author/Test SN SP +LR –LR QUADAS ICC

Cacchio et al11 … … … … 8 …

Puranen-Orava test 0.76 (0.61, 0.87) 0.82 (0.68, 0.92) 4.2 (NR) 0.29 (NR) … 0.84 (0.72, 0.87)

Bent-knee stretch test 0.84 (0.71, 0.93) 0.87 (0.73, 0.95) 6.5 (NR) 0.18 (NR) … 0.86 (0.78, 0.93)

Modified bent-knee stretch test 0.89 (0.76, 0.96) 0.91 (0.79, 0.97) 9.9 (NR) 0.12 (NR) … 0.88 (0.82, 0.94)

Zeren and Oztekin45† … … … … 6 …

Taking-off-the-shoe test 1.00 (0.97, 1.00) 1.00 (0.97, 1.00) 280.0 (17.6, 4454.6) 0.00 (0.00, 0.06) … NR

Active range-of-motion test 0.55 (0.46, 0.63) 1.00 (0.97, 1.00) 154.6 (9.7, 2468.7) 0.50 (0.38, 0.54) … NR

Passive range-of-motion test 0.57 (0.49, 0.66) 1.00 (0.97, 1.00) 160.6 (10.1, 2564.0) 0.43 (0.36, 0.52) … NR

Resisted range-of-motion test 0.61 (0.52, 0.69) 1.00 (0.97, 1.00) 170.6 (10.7, 2722.9) 0.40 (0.32, 0.49) … NR

Schneider-Kolsky et al37† … … … … 12 …

Composite clinical assessment 0.95 (0.83, 0.99) 0.03 (0.00, 0.22) 0.97 (0.88, 1.08) 1.9 (0.2, 16.0) … NR

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potential contributors to posterior thigh pain. Orthopaedic special tests for those patients with suspicion of a hamstring injury would, therefore, be valuable in identifying those patients with a ham-string injury.

Hence, the clinical utility of the vari-ous orthopaedic special tests investigated in this review requires careful consider-ation. Future studies should concentrate on investigating a set of tests with good diagnostic accuracy to either rule in or rule out hamstring injury as a potential cause of posterior thigh pain. Such tests, singly or in a cluster, could then comple-ment other tests that have been shown to be useful to identify posterior thigh pain due to the lumbar spine, sacroiliac joint, and piriformis syndrome, as previously mentioned. The diagnostic accuracy of these hamstring injury orthopaedic spe-cial tests would better be determined by future investigations with less bias. Fu-ture studies controlling for injury acute-ness assessment, blinding the results of diagnostic imaging, and reporting the reasons for study participant withdrawal would help limit this bias.

LimitationsA limitation of the present study is its use of stratified QUADAS scores to as-sess study quality. Although previous studies have used QUADAS summa-ry scores,14,22,23 others have cautioned against the use of a dedicated quality score.36 The 1 study ranked as high qual-ity could have potentially been inflated, as the QUADAS does not qualitatively score for sample size or a case-control design. The use of different reference standards may be a limitation in this re-view, although diagnostic US has been suggested to be as useful as, and more cost-effective than, MRI as a reference standard.13,38 Additional limitations in-clude limiting the studies to publica-tion in English and having only 1 author search the grey literature and pull data points, which increases the risk of poten-tial error. However, the other authors did verify the data points.

CONCLUSION

There are a limited number of studies and, therefore, tests that investigate the diagnostic accuracy

of orthopaedic special tests for ham-string injury in the athletic population. The diagnostic accuracy of these ortho-paedic special tests is quite variable. The Puranen-Orava, bent-knee stretch, and modified bent-knee stretch tests were found to alter posttest probability of a diagnosis to a small to moderate degree. The taking-off-the-shoe test was found to alter posttest probability to an almost conclusive degree, although the study investigating this test demonstrated the potential for significant bias. The use of a composite clinical assessment, although demonstrating high SN, only alters post-test probability to a degree less than minimal. Caution should be used when utilizing orthopaedic special tests for the diagnosis of hamstring injury, as diag-nostic accuracy of these tests is not well established. A comprehensive clinical ex-amination for diagnosis of posterior thigh pain attributable to hamstring injury that excludes other potential pain generators, versus reliance on these tests alone for decisive diagnostic clinical practice, is suggested. t

KEY POINTSFINDINGS: The findings from the few stud-ies that have looked at clinical diagnosis of hamstring injury suggest that single clinical examination orthopaedic special tests demonstrate stronger diagnostic than screening capability.IMPLICATIONS: Due to a dearth of, and potential bias in, the current literature, it is apparent that there is a need for high-quality diagnostic accuracy studies of clinical orthopaedic special tests for diagnosis of hamstring injury.CAUTION: Very few studies have investi-gated the application of clinical ortho-paedic special tests for hamstring injury. Further investigation is warranted prior to suggesting these tests as unequivocal methods of clinical assessment for pos-

terior thigh pain attributable to ham-string injury.

ACKNOWLEDGEMENTS: We would like to thank Carly Reiman for serving as a model; Holly R. Thompson, BA for her review; and Leila Ledbetter, MLIS for assisting with the litera-ture search for this study.

REFERENCES

1. Arnason A, Andersen TE, Holme I, Engebretsen L, Bahr R. Prevention of hamstring strains in elite soccer: an intervention study. Scand J Med Sci Sports. 2008;18:40-48. http://dx.doi.org/10.1111/j.1600-0838.2006.00634.x

2. Askling C, Saartok T, Thorstensson A. Type of acute hamstring strain affects flexibility, strength, and time to return to pre-injury level. Br J Sports Med. 2006;40:40-44. http://dx.doi.org/10.1136/bjsm.2005.018879

3. Askling CM, Nilsson J, Thorstensson A. A new hamstring test to complement the common clinical examination before return to sport after injury. Knee Surg Sports Traumatol Arthrosc. 2010;18:1798-1803. http://dx.doi.org/10.1007/s00167-010-1265-3

4. Askling CM, Tengvar M, Saartok T, Thorstensson A. Acute first-time hamstring strains during high-speed running: a longitudinal study includ-ing clinical and magnetic resonance imaging findings. Am J Sports Med. 2007;35:197-206. http://dx.doi.org/10.1177/0363546506294679

5. Askling CM, Tengvar M, Saartok T, Thorstensson A. Acute first-time hamstring strains during slow-speed stretching: clinical, magnetic reso-nance imaging, and recovery characteristics. Am J Sports Med. 2007;35:1716-1724. http://dx.doi.org/10.1177/0363546507303563

6. Askling CM, Tengvar M, Saartok T, Thorstens-son A. Proximal hamstring strains of stretch-ing type in different sports: injury situations, clinical and magnetic resonance imaging characteristics, and return to sport. Am J Sports Med. 2008;36:1799-1804. http://dx.doi.org/10.1177/0363546508315892

7. Blankenbaker DG, Tuite MJ. Temporal changes of muscle injury. Semin Musculoskelet Radiol. 2010;14:176-193. http://dx.doi.org/10.1055/s-0030-1253159

8. Brooks JH, Fuller CW, Kemp SP, Reddin DB. Epidemiology of injuries in English profes-sional rugby union: part 1 match injuries. Br J Sports Med. 2005;39:757-766. http://dx.doi.org/10.1136/bjsm.2005.018135

9. Brooks JH, Fuller CW, Kemp SP, Reddin DB. Epidemiology of injuries in English profes-sional rugby union: part 2 training injuries. Br J Sports Med. 2005;39:767-775. http://dx.doi.org/10.1136/bjsm.2005.018408

10. Brooks JH, Fuller CW, Kemp SP, Reddin DB.

43-04 Reiman.indd 227 3/20/2013 1:40:54 PM


[ research report ]

MORE INFORMATIONWWW.JOSPT.ORG@

Incidence, risk, and prevention of hamstring muscle injuries in professional rugby union. Am J Sports Med. 2006;34:1297-1306. http://dx.doi.org/10.1177/0363546505286022

11. Cacchio A, Borra F, Severini G, et al. Reliability and validity of three pain provocation tests used for the diagnosis of chronic proximal hamstring tendinopathy. Br J Sports Med. 2012;46:883-887. http://dx.doi.org/10.1136/bjsports-2011-090325

12. Clanton TO, Coupe KJ. Hamstring strains in athletes: diagnosis and treatment. J Am Acad Orthop Surg. 1998;6:237-248.

13. Connell DA, Schneider-Kolsky ME, Hoving JL, et al. Longitudinal study comparing sonographic and MRI assessments of acute and healing hamstring injuries. AJR Am J Roentgenol. 2004;183:975-984.

14. Cook C, Hegedus E. Diagnostic utility of clinical tests for spinal dysfunction. Man Ther. 2011;16:21-25. http://dx.doi.org/10.1016/j.math.2010.07.004

15. Cox DR. The Analysis of Binary Data. London, UK: Methuen; 1970.

16. Croisier JL, Ganteaume S, Binet J, Genty M, Ferret JM. Strength imbalances and preven-tion of hamstring injury in professional soccer players: a prospective study. Am J Sports Med. 2008;36:1469-1475. http://dx.doi.org/10.1177/0363546508316764

17. Deyo RA, Rainville J, Kent DL. What can the his-tory and physical examination tell us about low back pain? JAMA. 1992;268:760-765.

18. Donelson R, Aprill C, Medcalf R, Grant W. A pro-spective study of centralization of lumbar and referred pain. A predictor of symptomatic discs and anular competence. Spine (Phila Pa 1976). 1997;22:1115-1122.

19. Doust JA, Pietrzak E, Sanders S, Glasziou PP. Identifying studies for systematic reviews of diagnostic tests was difficult due to the poor sensitivity and precision of methodologic filters and the lack of information in the abstract. J Clin Epidemiol. 2005;58:444-449. http://dx.doi.org/10.1016/j.jclinepi.2004.09.011

20. Drezner JA. Practical management: ham-string muscle injuries. Clin J Sport Med. 2003;13:48-52.

21. Fishman LM, Dombi GW, Michaelsen C, et al. Piriformis syndrome: diagnosis, treatment, and outcome—a 10-year study. Arch Phys Med Reha-bil. 2002;83:295-301.

22. Hegedus EJ, Cook C, Hasselblad V, Goode A, McCrory DC. Physical examination tests for as-sessing a torn meniscus in the knee: a system-atic review with meta-analysis. J Orthop Sports Phys Ther. 2007;37:541-550. http://dx.doi.org/10.2519/jospt.2007.2560

23. Hegedus EJ, Goode A, Campbell S, et al. Physi-cal examination tests of the shoulder: a sys-tematic review with meta-analysis of individual tests. Br J Sports Med. 2008;42:80-92. http://dx.doi.org/10.1136/bjsm.2007.038406

24. Hoskins W, Pollard H. The management of hamstring injury—part 1: issues in diagnosis. Man Ther. 2005;10:96-107. http://dx.doi.org/10.1016/j.math.2005.03.006

25. Hunter DG, Speed CA. The assessment and management of chronic hamstring/posterior thigh pain. Best Pract Res Clin Rheumatol. 2007;21:261-277. http://dx.doi.org/10.1016/j.berh.2006.12.002

26. Jaeschke R, Guyatt GH, Sackett DL. Users’ guides to the medical literature. III. How to use an article about a diagnostic test. B. What are the results and will they help me in caring for my patients? The Evidence-Based Medicine Working Group. JAMA. 1994;271:703-707.

27. Landis JR, Koch GG. An application of hierarchi-cal kappa-type statistics in the assessment of majority agreement among multiple observers. Biometrics. 1977;33:363-374.

28. Laslett M, Öberg B, Aprill CN, McDonald B. Cen-tralization as a predictor of provocation discog-raphy results in chronic low back pain, and the influence of disability and distress on diagnostic power. Spine J. 2005;5:370-380. http://dx.doi.org/10.1016/j.spinee.2004.11.007

29. Laslett M, Young SB, Aprill CN, McDonald B. Diagnosing painful sacroiliac joints: a validity study of a McKenzie evaluation and sacroiliac provocation tests. Aust J Physiother. 2003;49:89-97.

30. Lehance C, Binet J, Bury T, Croisier JL. Muscular strength, functional performances and injury risk in professional and junior elite soccer players. Scand J Med Sci Sports. 2009;19:243-251. http://dx.doi.org/10.1111/j.1600-0838.2008.00780.x

31. Meeuwisse WH, Sellmer R, Hagel BE. Rates and risks of injury during intercollegiate basketball. Am J Sports Med. 2003;31:379-385.

32. Mendiguchia J, Brughelli M. A return-to-sport al-gorithm for acute hamstring injuries. Phys Ther Sport. 2011;12:2-14. http://dx.doi.org/10.1016/j.ptsp.2010.07.003

33. Moher D, Liberati A, Tetzlaff J, Altman DG. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Int J Surg. 2010;8:336-341. http://dx.doi.org/10.1016/j.ijsu.2010.02.007

34. Orchard J, Best TM, Verrall GM. Return to play following muscle strains. Clin J Sport Med. 2005;15:436-441.

35. Orchard J, Seward H. Epidemiology of injuries in the Australian Football League, seasons 1997-

2000. Br J Sports Med. 2002;36:39-44. 36. Rutjes AW, Reitsma JB, Di Nisio M, Smidt N,

van Rijn JC, Bossuyt PM. Evidence of bias and variation in diagnostic accuracy studies. CMAJ. 2006;174:469-476. http://dx.doi.org/10.1503/cmaj.050090

37. Schneider-Kolsky ME, Hoving JL, Warren P, Connell DA. A comparison between clinical assessment and magnetic resonance imag-ing of acute hamstring injuries. Am J Sports Med. 2006;34:1008-1015. http://dx.doi.org/10.1177/0363546505283835

38. Slavotinek JP. Muscle injury: the role of imaging in prognostic assignment and monitoring of muscle repair. Semin Musculo-skelet Radiol. 2010;14:194-200. http://dx.doi.org/10.1055/s-0030-1253160

39. Stankovic R, Johnell O, Maly P, Willner S. Use of lumbar extension, slump test, physical and neurological examination in the evaluation of patients with suspected herniated nucleus pulposus. A prospective clinical study. Man Ther. 1999;4:25-32.

40. Swartz MK. The PRISMA statement: a guideline for systematic reviews and meta-analyses. J Pediatr Health Care. 2011;25:1-2. http://dx.doi.org/10.1016/j.pedhc.2010.09.006

41. Verrall GM, Slavotinek JP, Barnes PG, Fon GT. Diagnostic and prognostic value of clinical findings in 83 athletes with posterior thigh injury: comparison of clinical findings with magnetic resonance imaging documentation of hamstring muscle strain. Am J Sports Med. 2003;31:969-973.

42. Vroomen PC, de Krom MC, Wilmink JT, Kester AD, Knottnerus JA. Diagnostic value of history and physical examination in patients suspected of lumbosacral nerve root compression. J Neu-rol Neurosurg Psychiatry. 2002;72:630-634.

43. Whiting P, Rutjes AW, Reitsma JB, Bossuyt PM, Kleijnen J. The development of QUADAS: a tool for the quality assessment of studies of diag-nostic accuracy included in systematic reviews. BMC Med Res Methodol. 2003;3:25. http://dx.doi.org/10.1186/1471-2288-3-25

44. Woods C, Hawkins RD, Maltby S, Hulse M, Thomas A, Hodson A. The Football Association Medical Research Programme: an audit of inju-ries in professional football—analysis of ham-string injuries. Br J Sports Med. 2004;38:36-41.

45. Zeren B, Oztekin HH. A new self-diagnostic test for biceps femoris muscle strains. Clin J Sport Med. 2006;16:166-169.

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DESCRIPTION OF THE ORTHOPAEDIC SPECIAL TESTS

Test Description Positive Finding Illustration

Puranen-Orava test • This test entails actively stretching the ham-string muscles in the standing position with the hip flexed at about 90°, the knee fully extended, and the foot on a solid support surface.

Exacerbation of the patient’s symptoms.

Puranen-Orava test.

Bent-knee stretch test

• The patient is supine. The hip and knee of the symptomatic limb are maximally flexed, and the clinician slowly straightens the knee while keeping the hip flexed.


Modified bent-knee stretch test

• The patient lies in the supine position with the lower extremities fully extended. The clinician grasps the symptomatic limb behind the heel with one hand and at the knee with the other. The clinician maximally flexes the hip and knee, and then rapidly straightens the knee.


Modified bent-knee stretch test, start position and finish position.

APPENDIX

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Taking-off-the-shoe test

• In standing, the patient is asked to take off the shoe on the affected side with the help of his/her other shoe. While performing this maneu-ver, the affected leg hindfoot must press the longitudinal arch of the noninvolved foot. The affected leg during the maneuver is in approxi-mately 90° of external rotation at the hip and 20° to 25° of flexion at the knee.

The feeling of a sharp pain over the injured biceps femoris.

Taking-off-the-shoe test: posterior view.

Active range-of-motion test

• Hip extension: in prone, the patient is asked to actively extend the hip with an extended knee.

• Knee flexion: in prone, the patient is asked to flex the knee as far as he/she can.

Reproduction of patient’s concordant pain with either test.

Passive range-of-motion test

• Passive hip flexion: the patient is supine, with the pelvis stabilized by grasping the iliac crest. As the hip is flexed, the knee is allowed to flex from the tension placed on the hamstrings and gravity. With pressure applied proximal to the knee joint, the normal end feel for hip flexion is soft owing to the approximation of the quadri-ceps with the abdomen.

• Passive knee extension: the patient is supine with the hip flexed to 90°, with the knee flexed in a relaxed position. The lower leg (below the knee) is passively extended to a firm muscle tension end point.


Resisted range-of-motion test

• Hip extension with an extended knee: the patient is prone, with the knee extended and the pelvis stabilized with pressure on the iliac crest. An isometric break test is performed at end-range hip extension, with resistance ap-plied to the popliteal fossa.


APPENDIX

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Resisted range-of-motion test (continued)

• Knee flexion: the patient is prone with the knee extended. An isometric break test is performed with the knee flexed to 10°, 45°, and 90° unless contraindicated. Clinician provides resistance over the Achilles tendon.

Composite clinical assessment

• Passive straight leg raise: with the patient’s lower extremity completely relaxed, the clini-cian lifts the lower extremity off the plinth with the knee fully extended. The degree of hip flex-ion is measured with a bubble goniometer.

• Active knee extension: the patient’s thigh is vertical with the posterior distal aspect of the thigh, resting lightly against a frame to keep the thigh perpendicular to the plinth. With the ankle relaxed in plantar flexion, the patient is asked to actively extend the knee while maintaining light contact with the horizontal part of the frame. A temporary myoclonus of alternating contraction and relaxation of the quadriceps and hamstring muscle groups tends to occur at the maximum angle of active knee extension. At this point, the patient is instructed not to force the leg past the point of initial mild resistance. The patient is then asked to slightly flex the knee until myoclonus ceases. At the first point at which the shaking ceases, the angle between the vertical and the tibia is recorded using an inclinometer.

• Manual muscle testing: manual muscle testing in the prone position is performed by asking the patient to lift his/her heel by bending his/her knee to the point at which the toe is off the couch. The patient is asked to hold that position while a gentle, steadily increasing resistance is applied to the heel (about 15° of knee flexion).

Reproduction of patient’s concordant pain/stiffness during any 1 of the 3 tests.

APPENDIX

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Hamstring Rehabilitation and Prevention Protocol University of Delaware Sports and Orthopedic Clinic

1/15

PREVENTATIVE EXERCISE PROGRESSION FOR

HAMSTRING STRAIN There are 4 components of a proper hamstring prevention program. These are aimed to incorporate the many ways that the hamstring is used in sport where it is most commonly injured; the muscle has the ability to stretch statically and dynamically, contract concentrically and eccentrically and also performs in rapid changes between the concentric and eccentric motions as in plyometric activity. **Before any activity, including stretching, it is important to warm up properly to increase blood flow to the muscles for effective stretching and to reduce the risk of injury. Examples of proper warm up include jogging, biking, jump rope, jumping jacks, etc.**

• Static stretching; should be performed for 30 seconds each with no ballistic movement at end range.

o Pike o Hurdles left and right o Straddle o Supine Hamstring stretch with belt o Standing Hamstring stretch with anterior pelvic tilt o Splits (gymnasts, cheerleaders, figure skaters, dancers, etc)

• Dynamic stretching; walking dynamic stretches should be performed for as many stretches as possible within approximately 10 yards.

Walking quad stretch Walking knee to chest Frankensteins Side Lunges

Walking hamstring stretch Inch Worms Helicoptors

Stepping Backwards


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Leg swings – these are performed stationary with one hand supported for balance. Swing straight leg forward until stretch is felt and then repeat into hip extension, progressively increasing the range.

Plyometrics: These are important exercises for the prevention of hamstring strain due to their ability to use the hamstring muscle at its greatest length and highest force. Please see plyometric program embedded in this rehabilitative program.

• Progressive Resistive Exercises are also required to increase the strength of the

hamstring to further prevent injury. Standing Hamstring curls Prone hamstring curls Concentric hamstring curls

Eccentric Hamstring curls Romanian Dead Lifts :


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REHABILITATION AND EXERCISE PROGRESSION AFTER GRADE II HAMSTRING STRAIN

Notes:

• Muscle most commonly affected is long head of the biceps femoris, usually just proximal to the musculotendinous junction 6-16 cm proximal to the knee joint.

• Immobilization if required should be in the lengthened position and should not last longer than 1 week

• The use of NSAIDS is controversial in the first few days because of the potential for impeding healing; evidence suggests that NSAIDs have no additive effect on the healing rate.

Acute Phase (3-4 times a day) • Rest (immobilization in a lengthened position for no longer than 1 week, then relative

rest) o No antalgia with gait: if antalgic, supplement with assistive device o Gentle stretching (pain less than 3/10)

• Ice in lengthened position (in long sitting with as much active pain free knee flexion and extension as possible)

• Compression and elevation until thigh girth stabilizes • NSAIDS no sooner than 2-4 days after injury • Retrograde massage may be implemented for swelling control. DTM may begin when

girth is stabilized • Modalities- sensory Estim can be used

Criteria for progression: No increase in thigh girth measured 8 cm proximal to the patella; SLR to 80˚ with an estimation of 3 or less on a numeric rating scale where 0 = no pain and 10 = maximal pain Test: The foot is plantar flexed and the examiner slowly (about 30˚/s) raises the leg Subacute Phase: day 3 to >3 weeks

• Stretching (3-4 times/day) o Progressively increase stretch to full ROM (stretched across hip and knee)

exercises. o Self stretching

Begin with standing technique with anterior pelvic tilt Progress to aggressive self-stretching and partner stretches

• Strengthening progression (daily) o Isometric knee flexion

begin with sub-maximal isometric holds at multiple joint angles (0o, 30o, 60o, 90o) and progress to maximal holds


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o Stool scoots Athlete sits on wheeled stool and plants heel into floor and uses hamstring

to propel forward. Progress with distance and to single leg.

o Start with Seated concentric isokinetic exercises (CON/ECC 50-75˚/s or isotonic) o Move towards higher and lower speeds with more force

o Seated hamstring curls

Begin at 30% of 1RM of contralateral hamstring 3-4 sets of 10 repetitions – progress to 60%

• Deep Tissue Massage (daily) o Depth and forcefulness may be increased as the

need arises to reach the target tissue that may be deeper

• Cardiovascular fitness (up to 2 sessions per day) o UBE o stationary biking o other controlled activities

• Modalities prn Criteria for progression within this phase: Complete the activity with estimation of 3 or less on a numeric rating scale where 0 = no pain and 10 = maximal pain. Complete concentric seated strengthening progression and achieve full ROM with estimation of 3 or less on a numeric rating scale where 0 = no pain and 10 = maximal pain. Remodeling Phase: 1-6 weeks

• Stretching progression (3-4 times/day) o Maintain or increase muscle length using aggressive frequent stretching

(passive, self and partner stretches) encourage exercise through the full ROM • Strengthening progression (daily to every other when at power volume)


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o Begin more aggressive concentric strengthening Seated hamstring curls

• 60-80% of 1RM of contralateral leg • Begin with strength volume (high

weight, low reps) and move to power volume (faster speeds)

Standing hamstring curls • Can be performed with machine or

ankle weights. • Begin with strength volume (high weight, low reps) and move to

power volume (faster speeds) o Prone hamstring exercises (introduces eccentric component)

Start with prone curls with ankle weights at 30% of 1RM of contralateral hamstring 3-4 sets of 10 repetitions.

Progress to strength and power volumes Progress to eccentric contraction via ankle weights with concentric

assistance or manual resistance.

o Manual prone eccentric/concentric hamstring curls Athlete lays prone while manual resistance is applied distally. He/She

contracts the hamstrings concentrically against resistance and continues to contract as resistance increases to bring the foot down eccentrically.

This allows for the athlete to be strengthened in pain free range and more focus can be paid to weakness in certain ranges, especially closer to full extension.

o Prone leg dropping

Athlete lies prone with knee flexed and foot in air. Gently move foot back and forth to stimulate relaxation. Drop the foot suddenly and have athlete catch the foot as soon as they feel it released. Progress to 1 or 2 lbs and/or push leg instead of drop to increase loading.


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This helps the athlete regain their proprioceptive sense that may have been lost secondary to weakness and immobilization from injury. With a heightened proprioceptive sense the athlete may be able to better detect the position of the hamstring, which may decrease their risk of re-injury.

o Progress to seated eccentric hamstring curl

Load weights at 120 % of 1 RM of single leg hamstring curl. Use two legs for concentric motion. Release one leg and allow single leg to release weight in a controlled fashion. Progress weights appropriately.

Progress to prone position o Progress to prone isokinetics (CON/ECC beginning at high speeds (240/240) and

gradually decreasing the speed (120, 90, and 60), through pain free range. Progress to strength and power volumes

o Hamstring ball rolls The athlete lays supine with a ball

under his/her leg(s). Roll the ball towards the body by

flexing the leg while maintaining trunk and hip stabilization.

This exercise can be progressed from

• 2 feet using theraball

• 1 foot using theraball

• 1 foot using medball, other foot in air.


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o Nordic hamstrings Athletes are kneeling with feet fixed. Instruct athlete to fall forward and use

hamstring to control descent for as long as possible then catch themselves on the table with their hands. Athlete forcefully pushes with hands to return to starting position to decrease concentric load to the hamstrings. With two people begin with maximum assistance using a belt around the athlete’s waist to assist them when they lean forward. With one person place theraball in front of patient to allow patient to push up and decrease the eccentric load

Progress by decreasing assistance, and increasing range until fall. Once patient can withstand whole range of motion, increase load by

adding speed to the starting phase. The partner can also push on the patient’s shoulder to increase difficulty. For variation person can hold down legs with different forces to load one side more than another

Plyometric progression In this case, plyometric exercise is used to strengthen the hamstrings while regaining the

neuromuscular properties needed to effectively perform sport specific activities. Plyometric exercise is based on the principle of utilizing the muscle’s stretch reflex with

stores energy through its eccentric phase of contraction. If utilized quickly, the energy stored can produce more force output during the concentric event. This brief moment between the two phases is the amortization phase. When performing plyometric exercise it is essential to perform a rapid eccentric phase to decrease the amortization time. They should be progressed systematically for proper overload; typically low intensity with high volume up to high intensity with low volume. It is also important to warm up properly in a plyometric fashion, which can be incorporated in the dynamic warm up. An appropriate plyometric warm up for these particular exercises include:

Marching Jogging Toe jogging to warm up a quick reaction time Straight leg jogging to prepare for impact exercises Butt kicks for stretching Exaggerated skipping These motions should also be progressed from 50% effort up to 100%

effort to decrease the risk of re-injury. This list is in order from easiest to hardest and should be progressed from one to

another when completed with 100% effort while abiding by previously stated criteria for progression.


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1. Cycle split jump a. Athlete stands in half lunge b. Perform jump, switching feet in the air with emphasis on pulling backwards

landing with feet opposite the starting position. c. Land and repeat jump with effort emphasized on decreasing the ground-

contact time.

2. Running Butt Kicks a. Begin running by flexing your knee and bringing your

heel back and around to your buttocks. Maintain a slight forward lean throughout the drill, and stay on the balls of your feet. Complete 20 kicks within 10 yards.

b. Maintain a quick, yet shallow arm swing, keep your elbows at 90° and drive your hands from chest to front hip pocket.

3. Running High Knees

a. Execute proper running form; keep your elbows at 90° and drive your hands up to chin level and back to your rear pocket. Stay on the balls of your feet, and drive your knees up as high as possible, and then down as quickly as possible.

4. Pogo jumps with knees to butt a. Athlete stands erect, feet comfortably

hips width apart b. Perform straight jump and pulls heels

towards the buttocks c. Land and repeat jump with effort

emphasized on decreasing the ground-contact time. T

5. Rollerboard Hamstring pulls a. Athlete lays supine with back on

rollerboard. b. The athlete’s legs are fixed either with a partner holding them or fixed to a

stationary object. c. The athlete then flexes and pushes away from his/her feet with emphasis

on decreasing the turn around time between flexion and extension


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6. Leg Swings (bent knee and straight knee) a. The athlete stands erect with one hand supported for balance. b. The athlete swings his/her leg forwards until he/she feels a slight stretch c. Quickly and powerfully push the leg down into full hip extension and let the

leg gently swing back into hip flexion with emphasis on decreasing the time between flexion and extension.

d. This can also be done with the knee flexed to isolate the hamstrings. Start by flexing the knee up, then extending it forward, forcefully bend the knee downwards until almost straight, and then continue to forcefully drive the leg up towards the butt with the knee bent. Then flex the hip to the starting position and repeat (Claw)

7. Heel toss with med ball a. Athlete is hanging from pull up bar with medball squeezed between his/her

heels b. From a stand still position, the athlete throws the ball backwards with

forceful hip extension and knee flexion. c. A partner must retrieve the ball and replace it between the athlete’s feet. d. This exercise can be progress by using a heavier medball.

8. Box step up and jump a. Place an 18" box in front of you. Place your right foot on top of the box.

Push off with your right foot and jump into the air. Land in the same position as you started. Perform the set then alternate legs.

b. Emphasize the quick contraction and minimal ground contact time to get as high as possible. Use your arms to help you explode up.

c. Variations: Perform with dumbbells or Turn 180-degrees in the air and land on opposite side of box


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9. Box Jumps

a. Stand facing a 12"-18" box. Keeping your feet together, jump up onto the box. Immediately hop back down and then explode back up in one movement emphasizing minimal ground contact time. Use your arms explosively to help propel you up and push off your toes.

b. Variations: Move on to higher boxes of 24" – 48". On the higher boxes always step down do not jump.

10. Depth Jumps a. Stand on top of a 12" box. Place a 12"-18" box about two YDS in front.

Drop down off the 12" box landing with your feet close together. Explode up onto the 12"-18" box and stick your landing. Step down and repeat the jump emphasizing rapid change in direction.

b. Keep your feet close together when landing on the ground or on the box. Bend your knees when landing on the ground and use your arms to help you explode up. Variations: Progress to higher boxes. 18" box on to 24" – 48" boxes.

11. Forward Depth Jumps in Series a. Set up a series of 6-8 boxes 12" - 48" high and ~1 YD apart. Begin by

standing atop the first box. Drop down to the ground and then explode up onto the second box. Continue through the series using your arms explosively decreasing ground contact time.

b. Variations: Perform the depth jump series laterally. Perform the depth jump series on single leg

.


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12. Forward Hurdle Hops – over and back a. Stand facing a series of 6-8 hurdles at 12"-18" high and one YD apart.

Hop over the first hurdle then over the second. As you land over the second hurdle, immediately hop backwards over the second hurdle, then forwards again decreasing the ground contact time. Use your arms explosively and tuck your knees into your chest. Maintain your balance by keeping your torso upright and your body’s center of gravity over the hurdle.

b. Hop over the third hurdle, then the fourth, now repeat over and back hop on the fourth hurdle. Carry on through the series performing over and back hops every other hurdle. (Hop forwards over "odd" number hurdles; hop over and back over "even" numbered ones.)

c. Variations: Explode into a 15-YD sprint, Go up for a header over the last hurdle and explode into a 15-YD sprint.

• Jogging/running progression o See attached for Field and Road Running Progression

Criteria for progression within this phase: Complete the activity with estimation of 3 or less on a numeric rating scale where 0 = no pain and 10 = maximal pain. Criteria for progression to next phase: Complete running progression. Able to perform 10 Nordic Hamstring exercises with minimum assist and no pain Return to activity: 2 weeks to 6 months

• Running activities are increase from jogging at low intensity to running and finally sprinting (please see attached running progression)

• High intensity plyometrics • Agility and sport/position specific drills (please see attached agility reference) MAINTAIN FLEXIBILITY AND CONTINUE PROTECTIVE ECCENTRIC PROGRAM


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Leng

th -

100

yard

s Length - 100 yards

Width - 50 yards

Width - 50 yards

Field Sports Running Progression (Distances based on 100 x 50 yard field)

Level 1 Walk ½ field then jog ½ field – repeat for 5 laps total Level 2 Walk ½ field then jog full field – repeat for 6 laps total (~1 mile) Level 3 Walk ½ field then jog 2 full fields – repeat for 9 laps total (~1.5 miles) Level 4 Walk ½ field then jog 3 full fields – repeat for 9 laps total (~1.5 miles) Level 5 Jog full 12 laps (~2 miles) Level 6 Jog full 15 laps (~2 ½ miles) Level 7 Jog full 18 laps (~3 miles) ** Levels 8 through 17 should be progressed to tolerance. Once at maximum level of time suggested continue to next level abiding by criteria for progression ** Level 8 Alternate between running and jogging every field and a half Level 9 Alternate between running and jogging every 2 fields Level 10 Run full 18 laps (3 miles) Level 11 Jog ½ field, then run ½ field, then sprint for width of field, then run ½ field and

repeat. – 12 laps (2 miles) Level 12 Run ½ field then sprint a width of a field and repeat – 10 times Level 13 Run ½ field then sprint a length of a field and repeat – 10 times Level 14 Jog ½ field then sprint a width of a field and repeat – 10 times Level 15 Jog ½ field then sprint a length of a field and repeat – 10 times Level 16 Sprint width of a field then rest 2 minutes and repeat – 10 times Level 17 Sprint length of a field then rest 2 minutes and repeat – 10

times

Soreness rules: (your pain)

• If sore during warm-up, take 2 days off and drop down 1 level • If sore during workout, take one day off and drop down 1 level • If sore after workout, stay at same level

Full Field = 300 yds


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Road Running Progression

Based 12 minute jogging mile/8 minute running mile Level 1 Walk 2 minutes then jog 2 minutes – repeat for total 35 minutes Level 2 Walk 2 minutes then jog 3 minutes – repeat for 32 minutes Level 3 Walk 2 minutes then jog 4 minutes – repeat for 30 minutes Level 4 Walk 2 minutes then jog 5 minutes – repeat for 28 minutes Level 5 Jog full 2 miles – 24 minutes Level 6 Jog full 2 ½ miles – 30 minutes Level 7 Jog full 3 miles – 36 minutes

** Levels 8 through 17 should be progressed to tolerance. Once at maximum level of time suggested continue to next level abiding by criteria for progression **

Level 8 Alternate running for 2 minutes and jogging for 3 minutes – 30 minutes Level 9 Alternate running for 5 minutes and jogging for 2 minutes – 28 minutes Level 10 Run full 3 miles – 24 minutes Level 11 Jog 2 minutes then run for 2 minutes then sprint for 30 seconds, then run 2

minutes and repeat – 30 minutes Level 12 Run 2 minutes sprint 15 seconds and repeat – 24 minutes Level 13 Run 2 minutes sprint 30 seconds and repeat – 24 minutes Level 14 Jog 2 minutes sprint 15 seconds and repeat – 24 minutes Level 15 Jog 2 minutes sprint 30 seconds and repeat – 24 minutes Level 16 Sprint 15 seconds then rest 2 minutes – 24 minutes Level 17 Sprint 30 seconds then rest 3 minutes – 24 minutes

Soreness rules: (your pain)

• If sore during warm-up, take 2 days off and drop down 1 level • If sore during workout, take one day off and drop down 1 level • If sore after workout, stay at same level


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Agility Drills Progression • Backward Running

o Run backwards, progressing distance, speed, and % effort • Ladder High Knees

o Run through ladder with maximal hip and knee flexion increasing speed and % effort

• Back Ladder o Run through ladder backwards increasing speed and % effort

• Cross Ladder o Start on L side of ladder, place R foot in ladder,

followed by L, place R foot out of ladder followed by L. Place L foot back into ladder, followed by R, place L foot out of ladder followed by R. Repeat until end of ladder. Progress by increasing speed and % effort.

• 20 Yard Square o Start in 2 pt stance,

sprint five yards to first cone make sharp R cut. Shuffle R five yards, make sharp cut back. Backpedal 5 yds to next cone, make sharp cut L. L shuffle through finish.

• In and Out Shuffle o Start in 2 pt stance;

stand on side of the ladder facing the first box. Jump with both feet into first

box, then back to starting position, then jump to second box, and jump straight backwards, repeat pattern through ladder

• Flip and Catch o Start in standing position, placing medicine ball

tightly between both feet. Proceed to jump into the air, kicking the ball into the air behind you. After landing quickly turn and catch the ball before it hits the ground.

There exercises can be modified to meet sport and positions specific demands.


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References Askling C, Karlsson J, Thorstensson A. Hamstring injury occurrence in elite soccer players

after preseason strength training with eccentric overload. Scand J Med Sci Sports. 2003 Aug;13(4):244-50.

Askling C, Saartok T, Thorstensson A. Type of acute hamstring strain affects flexibility, strength, and time to return to pre-injury level. Br J Sports Med. 2006 Jan;40(1):40-4.

Baechle T, Earle R. Essentials of Strength and Conditioning, 2nd Edition. Hong Kong: Human Kinetics. 2000

Brown L, Ferrigno V, Santana J. Training for speed, agility, and quickness. United States: Human Kinetics. 2000.

Chu D. Jumping into plyometrics. United States: Leisure Press. 1992 Kaminski T, Wabbersen C, Murphy R. Concentric Versus Enhanced Eccentric Hamstring

Strength Training: Clinical Implications. J Athl Train. 1998 Jul;33(3):216-221 LaStayo P, Woolf J, Lewek M, Snyder-Mackler L, Reich T, Lindstedt S. Eccentric muscle

contractions: their contribution to injury, prevention, rehabilitation, and sport. J Orthop Sports Phys Ther. 2003 Oct;33(10):557-71.

Mjolsnes R, Arnason A, Osthagen T, Raastad T, Bahr R. A 10-week randomized trial comparing eccentric vs. concentric hamstring strength training in well-trained soccer players. Scand J Med Sci Sports. 2004:14:311-317.

Peterson J, Holmich P. Evidence based prevention of hamstring injuries in sport. Br J Sports Med. 2005 Jun;39(6):319-23.

Radcliff J, Farentinos R. High-powered Plyometrics. Champaign, IL: Human Kinetics. 1999. Werner, Gregory A., “JMU Strength and Conditioning – Plyometric Training.” 2004

http://orgs.jmu.edu/strength/JMU_Summer_2000_WebPage/JMU_Summer_2000_Sections/10P_Summer_Plyometric_Training_Info.htm

Worrell T. Factors associated with hamstring injuries. An approach to treatment and preventative measures. Sports Med. 1994 May;17(5):338-45.

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