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ARTICLE IN PRESSG ModelSAMS-1036; No. of Pages 6

Journal of Science and Medicine in Sport xxx (2014) xxx–xxx

Contents lists available at ScienceDirect

Journal of Science and Medicine in Sport

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ffects of external pelvic compression on isokinetic strength of thehigh muscles in sportsmen with and without hamstring injuries

shokan Arumugama,∗, Stephan Milosavljevicb, Stephanie Woodleyc, Gisela Solea

School of Physiotherapy, University of Otago, New ZealandSchool of Physical Therapy, University of Saskatchewan, CanadaDepartment of Anatomy, University of Otago, New Zealand

a r t i c l e i n f o

rticle history:eceived 30 December 2013eceived in revised form 7 May 2014ccepted 17 May 2014vailable online xxx

eywords:thletic injuryuscle strength dynamometerrthotic devices

a b s t r a c t

Objectives: To investigate whether application of a pelvic compression belt affects isokinetic strength ofthe thigh muscles in sportsmen with and without hamstring injuries.Design: Randomized crossover, cross-sectional.Methods: Twenty sportsmen (age 22.0 ± 1.5 years) with hamstring injuries (hamstring-injured group)and 29 (age 23.5 ± 1.5 years) without hamstring injuries (control group) underwent isokinetic testingof the thigh muscles. Testing included five reciprocal concentric quadriceps and hamstring contractions,and five eccentric hamstring contractions at an angular velocity of 60◦/s, with and without a pelviccompression belt in randomized order. The outcome measures were average torque normalized to body-weight for terminal range eccentric hamstring contractions and peak torque normalized to bodyweightfor concentric quadriceps, concentric hamstring and eccentric hamstring contractions.Results: There was a significant increase in normalized average torque of eccentric hamstring contrac-tions in the terminal range for both groups (p ≤ 0.044) and normalized peak torque of eccentric hamstringcontractions for injured hamstrings (p = 0.025) while wearing the pelvic compression belt. No significantchanges were found for other torque variables. Injured hamstrings were weaker than the contralateraluninjured hamstrings during terminal range eccentric hamstring (p = 0.040), and concentric hamstring(p = 0.020) contractions recorded without the pelvic compression belt. However, no between-group dif-
ferences were found for any of the investigated variables.Conclusion: Wearing the pelvic compression belt appears to have a facilitatory effect on terminal rangeeccentric hamstring strength in sportsmen with and without hamstring injuries. Future investigationsshould ascertain whether there is a role for using a pelvic compression belt for rehabilitation of hamstringinjuries.
© 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

. Introduction

Hamstring injury is reported to most commonly occur inither the terminal stance1 or swing phases1,2 of sprinting, asso-iated with eccentric loading and lengthening of this bi-articularuscle group. Injured hamstrings also exhibit decreased torque

nd electromyographic (EMG) activity in the terminal range ofccentric isokinetic contractions.3 Assessment and rehabilitation

Please cite this article in press as: Arumugam A, et al. Effects of externin sportsmen with and without hamstring injuries. J Sci Med Sport (20

f hamstring injuries include multi-factorial strategies includingxamination of hamstring neuromotor control and strength. Recentiterature has also emphasized examination of lumbopelvic spine

∗ Corresponding author.E-mail addresses: [email protected], [email protected]

A. Arumugam).

ttp://dx.doi.org/10.1016/j.jsams.2014.05.009440-2440/© 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserve

biomechanics and motor control as potential factors contributing tohamstring injury.4 Moreover, an increase in isokinetic concentricpeak torque of injured hamstrings following manipulation of thesacroiliac joint (SIJ) has been reported.5 Anatomically, the proximaltendon of the biceps femoris (long head) is continuous in part withthe sacrotuberous ligament.6 Thus, there appears to be a functionalrelationship between the hamstring muscles and the lumbopelvicspine.

The use of a pelvic compression belt (PCB) is found to directlyinfluence stability and mobility of the SIJ,7 and also claimed toindirectly influence function of the hamstrings.8 While applica-tion of a PCB appears to affect hamstring neuromotor control

al pelvic compression on isokinetic strength of the thigh muscles14), http://dx.doi.org/10.1016/j.jsams.2014.05.009

and strength,7,8 these relationships need to be explored fur-ther. Weakness of injured hamstrings has been hypotheticallylinked to injury recurrence9 and, if so, there may be somemerit in examining the effects of external pelvic compression on

d.

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dx.doi.org/10.1016/j.jsams.2014.05.009

http://www.sciencedirect.com/science/journal/14402440

http://www.elsevier.com/locate/jsams

mailto:[email protected]

mailto:[email protected]

dx.doi.org/10.1016/j.jsams.2014.05.009

IN PRESSG ModelJ

2 e and Medicine in Sport xxx (2014) xxx–xxx

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ARTICLESAMS-1036; No. of Pages 6

A. Arumugam et al. / Journal of Scienc

amstring neuromotor control as part of a multi-modal interven-ion plan.

According to a recent systematic review,7 studies have investi-ated the effects of external pelvic compression on the isometrictrength of muscles during a task (for example during lifting, andhe active straight leg raise) or certain muscle groups (low back, hipdductor) in individuals with or without lumbopelvic dysfunction.here is some evidence that interventions (manipulation) directedt the SIJ/lumbopelvic joints can affect thigh muscle strength5,10

upporting an argument for a neuromotor link between the pelvicnd thigh regions. These putative structural and neuroreflexiveinks between the hamstrings, pelvis and lumbar spine provide aesearch focus to determine whether application of a pelvic com-ression belt (PCB) can alter the isokinetic strength of the thighuscles in sportsmen with and without hamstring injuries.

. Methods

A randomized cross-over experimental design was used and thetudy was conducted in the Mark Steptoe Laboratory of the Schoolf Physiotherapy at the University of Otago. Ethical approval wasranted by the University of Otago Human Ethics Committee (Ref-rence no. 11/115) and written informed consent was obtainedrom all participants.

Participants aged between 18 and 35 years were recruited bymail, word of mouth, and adverts displayed around the University.portsmen were included in the hamstring-injured group based onelf-report of injury3,11 if they had experienced an immediate onsetf pain in the posterior aspect of the thigh while playing sport12

ithin the previous 12 months, but not less than a month; thenjury necessitated intervention from a health professional and pre-ented participation in at least one match or competition,13 or ateast one week of usual sports training,14 within the previous 12

onths. Unilateral or bilateral, first-time or recurrent hamstringnjuries were eligible for inclusion. Sportsmen without any previ-usly diagnosed hamstring injury were recruited for the controlroup. A known history of trauma/dysfunction in the lower limbother than hamstring injury) or lumbopelvic region within the pre-ious six months that required intervention by a health professionalxcluded potential participants from both groups. Further, thoseith any evidence of abnormal signs and symptoms (other than

hose related to hamstring injuries) during clinical examinationf the lumbopelvic region and/or the lower limb were excluded.he ability of sportsmen to recall the history of injury within therevious 12 months has been reported to be valid11 and, there-ore, participants were recruited based on their self-declaration ofistory of hamstring injury.

Before isokinetic testing, anthropometric measurementsheight, body mass and 4-point skin fold measures) were recorded.o estimate body fat percentage, skin fold measurements wereaken using calipers (Slim Guide® caliper, Creative Health Products,

I) for the triceps, infrascapular, suprailiac and mid-thigh regionssing standard guidelines.15 The sit-and-reach test was used tossess bilateral hamstring flexibility.16

Isokinetic tests were performed under two conditions, withnd without the PCB. Data were collected from both sides for theamstring-injured participants and only one side (left or right) forhe control participants. The leg to be tested and the order of testonditions (PCB vs. no PCB) were randomized using computer gen-rated numbers.

The PCB (SI-brace neoprene-ADL-anatomisch; Rafys, The


etherlands) was applied just below the anterior superior iliacpines (Fig. 1),7,17 and tightened maximally by the primary inves-igator (AA) without any discomfort to participants. The amountf PCB tension achieved during isokinetic tests was recorded using

Fig. 1. Position of the pelvic compression belt as used in the study.

a load cell in a separate study on 10 healthy men. The mean PCBtension was found to be 63.43 (±9.90) N for reciprocal concentricquadriceps (ConQ) and concentric hamstrings (ConH) contractions,and 49.78 (±5.70) N for eccentric hamstring (EccH) contractions.Participants walked around the room between the conditions forat least 5 min18 to provide an adequate wash-out effect.

A warm-up of 5 min of static cycling (60 rpm) was undertakenprior to testing. Participants were then seated on a BiodexTM sys-tem 3 pro isokinetic dynamometer (Biodex Medical systems, NY)with a trunk-hip angle of 100◦ (Supplementary Fig. 1). The mechan-ical axis of rotation of the dynamometer was aligned with thelateral femoral epicondyle, and the shin pad was placed about 2 cmabove the medial malleolus. The effect of gravity on the leg wasadjusted using the Biodex software after placing the knee between25◦ and 30◦ of extension. Participants were familiarized with thedynamometer and a warm-up of the thigh muscles included aminimum of 10 sub-maximal contractions followed by two maxi-mal concentric and eccentric contractions at 60◦/s.3 Five reciprocalConQ and ConH maximal contractions were then performed at anangular velocity of 60◦/s followed by five EccH contractions at 60◦/s.The torque and velocity data were recorded at 200 Hz with theBiodex software (version 3.30), within a range of motion of 90◦ dur-ing each contraction: 0◦ of extension (starting position) to 90◦ offlexion (end position) for ConH, and 90◦ of flexion to 0◦ of extensionfor ConQ and EccH contractions. A rest period of 2 min was allowedbetween concentric and eccentric trials to minimize fatigue.19

Supplementary material related to this article can be found, inthe online version, at doi:10.1016/j.jsams.2014.05.009.

Outcome measures included (gravity-corrected) peak torque(PT) normalized to bodyweight for ConQ, ConH and EccH contrac-tions, average torque normalized to bodyweight for the terminalrange of EccH contractions, and the functional torque ratio (PTEccH:PT ConQ). Further, the torque data of EccH contractionwere analyzed from 85◦ to 5◦ knee flexion using a 50 ms epochsapproach; the initial and terminal 5◦ were omitted because theyare essentially non-isokinetic. The outer range (≈25–5◦ of kneeextension) corresponded to the last six 50 ms epochs.3 The averagetorque of the terminal movement quartile from five repetitions was


normalized to bodyweight to allow comparison between the testconditions (PCB vs. no PCB). The obtained value was multiplied by100 to ensure consistency with the results of the Biodex software.20

As the knee joint angle can vary from 20◦ to 33◦ compared to

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Table 1Demographic and anthropometric data and sports participation of participants.

Variable HIG (n = 20) CG (n = 29)

Age (years), mean (SD) 22.0 (1.5) 23.5 (1.5)

Anthropometric measurements, mean (SD)Body weight (kg) 85.5 (14.4) 71.2 (10.9)Height (m) 1.81 (0.08) 1.76 (0.08)BMI (kg/m2) 25.9 (3.4) 22.9 (2.7)Body fat (%) 23.3 (3.4) 23.6 (4.4)

Flexibility, mean (SD)Sit-and-reach (cm) 23.1 (6.5) 23.8 (11.3)

Sports participation, n (%)Rugby 9(45) 2 (7)Soccer/football 8 (40) 10 (35)Hockey 1 (5) 4 (14)Ice hockey 0 (0) 1 (3)Sprinting 1 (5) 1 (3)Long distance running 0 (0) 2 (7)Triathlon 0 (0) 1 (3)Weight-lifting 0 (0) 2 (7)Racquet sports 1 (5) 2 (7)Cricket 0 (0) 2 (7)

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Table 2Data relating to hamstring injuries.

Characteristic, n (%)a Number(except where indicated)

Unilateral injury 17 (85)b

Bilateral injury 3 (15)c

Recurrent injury 10 (50)d

Imaging investigationMagnetic resonance imaging 1 (5)Ultrasound 1 (5)No imaging 18 (90)

Treatment historyPhysiotherapy 19 (95)Osteopathy 1 (5)

Injured legPreferred side 13 (57)Nonpreferred side 10 (43)

Muscle injuredBiceps femoris 11 (48)Medial hamstring 12 (52)

Severity of injurye

Minor 5 (25)Moderate 6 (30)Severe 9 (45)

Time since recent injury (months), mean (SD) 4.85 (3.97)Time taken off from sports training due to

injury (weeks), mean (SD)3.55 (2.24)

Strength deficit of injured limb compared to uninjured limb in participantswith unilateral hamstring injury, mean (CI) (Nm/kg)

Terminal range EccHf (25–5◦) −18.63 (−36.27 to −1.00)ConQ PTg −12.96 (−35.77 to 9.85)ConH PTg −10.12 (−18.46 to −1.78)EccH PTg −13.83 (−31.11 to 3.44)

ConH, concentric hamstring contraction; ConQ, concentric quadriceps contraction;CG, control group; CI, confidence interval; EccH, eccentric hamstring contraction;PT, peak torque.Bold values indicate statistically significant findings (p < 0.050).

a Hamstring injury history based on self-report.b One participant underwent an anterior cruciate ligament reconstruction surgery

with bone-patellar tendon-bone graft one year prior to the onset of hamstring injury.c Time of onset of injury was more than 12 months for one side of a participant.d Time of these injuries ranged between 3 months and 5 years prior to the recent

injury.e The severity of hamstring injury has been classified using the period of absence

from sports participation as minor (≤7 days), moderate (8–21 days) or severe (>21

Basket ball 0 (0) 2 (7)

G, control group and HIG, hamstring-injured group.

ynamometer lever angle,3,21 the range of motion was calculatedased on time instead of dynamometer lever angle.

The effects of the PCB on dependent variables were investigatedsing paired t-tests; the between-group comparison of magnitudef change induced by the PCB was done using independent t-testsor any variable showing significant difference between the testonditions among groups. In addition, independent t-tests weresed to explore between-group differences, and paired t-tests toompare within-group differences for the trials without the PCB. Alltatistical analyses were performed using the IBM-SPSS softwareVersion 20, IBM, NY).

To compute effect size (d) for estimating the magnitude ofhange induced by the PCB on the dependent variables, the for-ula devised by Cohen22 was used, assuming that the SDs of

he test conditions were not different. The following index wassed to interpret effect sizes: small (0.20 ≤ d ≤ 0.50), medium0.50 ≤ d ≤ 0.80) and large (≥0.80).22

. Results

Twenty sportsmen with hamstring injuries and 29 healthyportsmen were included in the hamstring-injured group and con-rol group, respectively. Demographic and anthropometric datand sporting activities of all participants are presented in Table 1nd history relevant to those in the hamstring-injured group andtrength differences between limbs in unilateral hamstring-injuredarticipants are summarized in Table 2. Three participants hadilateral hamstring injuries. Among them, the onset of injury forne limb of one participant did not occur within the required2 month timeframe and, therefore, this limb was excluded fromtatistical analyses. There was no significant difference betweenhe two groups for body fat (%) (p = 0.835); however, significantifferences were found for height, weight and BMI (p < 0.050).herefore, instead of absolute values, normalization using body-eight was used to reduce inter-subject variability within- and

etween-groups.All participants in the hamstring-injured group had returned

ither partially or fully to sports training prior to data collection.


ix reported continued discomfort during moderate exertion orports activities. Six others reported minor discomfort and/or sore-ess of the injured hamstrings during or after strenuous/sportingctivities. The remaining four participants described that they had

days).35

f Average torque normalized to bodyweight multiplied by 100.g Peak torque normalized to bodyweight multiplied by 100.

returned to a level of pre-injury training. Four participants werestill undergoing rehabilitative exercises prescribed by a physiother-apist.

There was a significant increase in the normalized averagetorque for EccH contractions in the terminal range for participantswith (p = 0.003) and without hamstring injury (p = 0.044), amount-ing to 18.07 Nm/kg (10%) and 10.08 Nm/kg (5%), respectively, whilewearing the PCB (d ≤ 0.33, Table 3). The magnitude of increasewith the PCB was not significantly different between the groups(p = 0.275). In addition, with application of the PCB there was a sig-nificant increase in normalized PT value of EccH contractions for theinjured side by 11.44 Nm/kg (5%), but not for other contractions, inthe hamstring-injured (p = 0.025, d = 0.22) but not the control group(p = 0.313, Table 3). There was no significant difference between thetest conditions for normalized PT values of ConQ and ConH contrac-tions, and the functional torque ratio (EccH:ConQ) for participants


in both groups.Additional findings from the study are shown in a supplemen-

tary Table. Normalized torque values and the functional toque ratiodid not show statistically significant between-group differences.

dx.doi.org/10.1016/j.jsams.2014.05.009


ARTICLE ING ModelJSAMS-1036; No. of Pages 6

4 A. Arumugam et al. / Journal of Science and

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PRESSMedicine in Sport xxx (2014) xxx–xxx

However, the injured side was significantly weaker than the con-tralateral uninjured side by 18.63 Nm/kg (10%) during the terminalrange of EccH contractions (p = 0.040, d = 0.34) and by 10.12 Nm/kg(7%) (p = 0.020, d = 0.27) during ConH contractions (Table 2). No sta-tistically significant differences were noted between sides for othertype of contractions.


4. Discussion

The application of the PCB resulted in a significant increase ineccentric strength of the hamstrings in the outer range for bothparticipant groups. Specifically, eccentric strength of the injuredhamstrings was found to be weaker by 10% in the terminal rangecompared to the uninjured (contralateral) hamstrings (Table 2)and wearing a PCB was found to improve this by an average of10% (Table 3). The magnitude of change induced by the PCB in thehamstring-injured group (supplementary Fig. 2A) was not signifi-cantly different from the control group (supplementary Fig. 2B). Thehamstring-injured group included participants undergoing finalstages of rehabilitation and those who had already fully returned tosports training. This could have accounted for variations in injuredparticipants responses to the PCB resulting in an overall small effectsize (d = 0.33). With the PCB, there was also an increase in normal-ized EccH PT for the injured side of the hamstring-injured group(5%) but not for the control participants.


The results of this study indicate that a PCB applied to thepelvis can affect eccentric hamstring muscle performance. Previousstudies have investigated the effects of other interventions, suchas manipulation, applied to the lumbopelvic spine on strength ofthe thigh muscles.5,10 In the current study, there was no evidenceof any change in normalized PT of ConQ and ConH contractionswith the application of the PCB in sportsmen with and withouthamstring injury. Cibulka et al.5 documented an increase in ConHPT for injured hamstrings following manipulation of the SIJ in 10participants, while no significant change was found for ConQ con-tractions. The effect size for ConH PT in Cibulka et al.’s5 study wasalso small (d = 0.46) although the percentage change was equiv-alent to 22% for ConH PT. Other studies reported an immediateincrease in quadriceps strength up to 3% in healthy individuals(n = 13)10 and 12% (n = 18)23 in individuals with anterior kneepain/patellofemoral pain syndrome following lumbopelvic and SIJmanipulation, respectively. However, the test conditions (manip-ulation vs. no manipulation) were not randomized in any of thesestudies. Irrespective of the differences in methods and interven-tion used, all of these studies confirm a putative neuromotor linkbetween the pelvis and thigh muscles. The latent effects of SIJmanipulation on increased thigh muscle strength are transient andthe neuroreflexive pathway is uncertain10; whether similar effectsfrom external pelvic compression can be sustained while wearingthe PCB needs further investigation.

Various biomechanical and neurophysiologic mechanisms sup-porting the effects of the PCB on strength of hamstrings have beenhypothesized.8 It is proposed that application of a PCB below theanterior superior iliac spines can decrease sacral nutation24 byexerting pressure on the posteroinferior aspect of the sacrum,25

potentially leading to decreased tension of the long head of bicepsfemoris following relaxation of the sacrotuberous ligament.8 There


is some evidence that a decrease in passive hamstring stiffness(≈22%) occurs following core stability training.26 Thus, a reductionin hamstring stiffness secondary to an improvement in lum-bopelvic stability is plausible. Similarly, application of the PCB

dx.doi.org/10.1016/j.jsams.2014.05.009



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ight lead to a relative decrease in hamstring stiffness resultingrom the extrinsic (reflexive) and/or intrinsic (active sarcom-res and passive connective tissue) components leading to anncrease in the eccentric torque in the lengthened range. In addi-ion to contractile components of the hamstrings, the contributionf non-contractile components play an important role in resul-ant torque generated during isokinetic testing in the lengthenedanges.8

As the innervation of the SIJ (L2–S4), quadriceps (L2–L4) andamstrings (L5–S2) share some common nerve root levels, it isrgued that altering the sensory input to one structure could pos-ibly influence motor output of all the structures that receivennervation from the same root levels.27 The effects of externalelvic compression might suppress descending inhibitory mech-nisms resulting from nociceptors by blocking the pain gatet the spinal cord28 and, in turn, enhance the performance ofamstrings in those with hamstring injury. Pressure on bodyarts has been reported to stimulate descending pain inhibitoryystems in the central nervous system29 and the PCB might pro-uce similar effects. The mechanisms underpinning peripheralypoalgesic response induced in limbs following external pelvicompression and following spinal mobilization30 could hypothet-cally be similar. Though spinal mobilization and external pelvicompression have different mechanical stimuli, the initial effectsf interventions on the spine have been reported to have aympathoexcitation mediated hypolagesia specifically focused onechanical nociception.30 This will need further validation for

xternal pelvic compression.There were no statistically significant differences between

roups for any of the isokinetic variables obtained during tri-ls without the PCB (supplementary Table). These results agreeith previous findings for PT and torque ratios (conventional

nd/or functional ratios) between hamstring-injured and controlarticipants.14,31 Sole et al. reported significant differences in outerange eccentric hamstring torque between the injured and con-rol participants of their study.3 Another study concluded thatamstring-injured participants show decreased EccH PT at fast andlower velocities, and decreased ConH and ConQ PTs at slowerelocities than the control participants.32 The average absencerom sports participation due to injury was nearly 2 months inhe study by Jonhagen et al.32 as opposed to other studies and theurrent investigation (range: 2–4 weeks). This reflects that theirarticipants could have had severe injuries with more functional

imitations than others, thus contributing to the differences in find-ngs between the studies. However, these additional findings onetween-group differences should be interpreted after consideringhe fact that groups are different in height, weight and BMI becausehe number of rugby players in the hamstring-injured group (45%)as greater than the healthy group (7%) in this study. Exploring

his further is neither the aim of this study nor within the scope ofhis article.

Though the mean increase in terminal range eccentric torqueas 10% for the hamstring-injured group, the range for this

hange was 44% to −13% for individual participants which indi-ate individual-specific responses to the PCB. In clinical practice,t would need to be assessed on an individual basis whetherhe sportsperson with a hamstring injury responds positively tohe PCB in terms of symptoms and strength output, and prag-

atically decide to intervene with the PCB as an adjunct forehabilitation. A previous study indicated that trunk stabiliza-ion exercises decrease the risk for hamstring injury recurrence.33

hether the application of a belt as an adjunct to the exer-


ises might have similar effects could be evaluated. Further,earing the belt for longer periods and effects thereof at a func-

ional level rather than just at an impairment level could bexplored.

PRESSMedicine in Sport xxx (2014) xxx–xxx 5

Participants in the hamstring-injured group were recruitedbased on their self-reported history of hamstring injury with eli-gibility confirmed based on reproduction of symptoms wheneverpossible during clinical examination and previous diagnosis ofinjury by a health professional. Only two of the 20 participantsunderwent imaging investigations while the others were diagnosedand managed clinically (Table 2). As this study recruited mainlycommunity-level sportsmen, imaging was not possible as part ofstandard care. Five participants, clinically diagnosed with ham-string injuries, were classified as having minor injuries based onthe period of absence from sports participation (Table 2). Moreover,approximately 30% of athletes with clinically diagnosed minor ormoderate hamstring injuries are likely to have no MRI evidence ofinjury.34 Thus, our results apply to athletes with a clinical diagnosisof hamstring injury without confirmation of changes on imaging.

Assessment of psychosocial factors (including emotionalresponses), functional limitations, and kinesiophobia could helpin understanding the influence of these factors on neuromuscu-lar performance of (injured) hamstrings. Being a cross-sectionaland cross-over study, immediate effects on neuromotor control ofthe lumbopelvic and hamstring muscles were assessed before andafter application of the PCB without considering possible psychoso-cial influences. However, while examining baseline differencesbetween groups these factors might be important and warrantinvestigation in a future study.

5. Conclusion

Increased eccentric flexor torque in the lengthened range wasfound for sportsmen with and without recent hamstring injurieswith application of a PCB; however, the magnitude of increase wasnot significantly different between groups. There was a deficit ineccentric torque in the lengthened range, and concentric (peak)torque of injured hamstrings compared to uninjured hamstrings.Future studies would need to confirm whether or not these resid-ual strength deficits predispose to further injury. The current studybeing a cross-sectional investigation cannot imply directly whetherthe PCB can be used for eccentric training of the hamstrings whichwarrants further investigation.

Practical implications

• Injured hamstrings were found to be significantly weaker thanuninjured hamstrings during terminal range eccentric (10%), andconcentric hamstring (7%) contractions in sportsmen with uni-lateral hamstring injury.

• Application of a pelvic compression belt significantly increasedterminal range eccentric strength of injured hamstrings by 10%in sportsmen with hamstring injury and uninjured hamstrings by5% in healthy sportsmen.

• Application of a pelvic compression belt did not change concen-tric (peak) torque of the quadriceps and hamstring muscles insportsmen with and without hamstring injury.

Ethical approval

The University of Otago Human Ethics Committee approved thisstudy. Written informed consent was obtained from all participantsbefore data collection began.

Funding


An internal grant from the Mark Steptoe Memorial Trust ofSchool of Physiotherapy, University of Otago; no external fundingwas received.

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onflict of interest

There is no conflict of interest that could have influenced thistudy.

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