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Timmins RG, Shield AJ, Williams MD, Lorenzen C, Opar DA. Architectural adaptations of muscle to training and injury: a narrative review outlining the contributions by fascicle length, pennation angle and muscle thickness. Br J Sports Med 2016; 50:1467-1472. [DOI: 10.1136/bjsports-2015-094881] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/22/2015] [Indexed: 01/06/2023]
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Valle X, L.Tol J, Hamilton B, Rodas G, Malliaras P, Malliaropoulos N, Rizo V, Moreno M, Jardi J. Hamstring Muscle Injuries, a Rehabilitation Protocol Purpose. Asian J Sports Med 2015; 6:e25411. [PMID: 26715969 PMCID: PMC4691307 DOI: 10.5812/asjsm.25411] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 01/28/2015] [Accepted: 02/06/2015] [Indexed: 11/22/2022] Open
Abstract
Context: Hamstring acute muscle injuries are prevalent in several sports including AFL football (Australian Football League), sprinting and soccer, and are often associated with prolonged time away from sport. Evidence Acquisition: In response to this, research into prevention and management of hamstring injury has increased, but epidemiological data shows no decline in injury and re-injury rates, suggesting that rehabilitation programs and return to play (RTP) criteria have to be improved. There continues to be a lack of consensus regarding how to assess performance, recovery and readiness to RTP, following hamstring strain injury. Results: The aim of this paper was to propose rehabilitation protocol for hamstring muscle injuries based on current basic science and research knowledge regarding injury demographics and management options. Conclusions: Criteria-based (subjective and objective) progression through the rehabilitation program will be outlined along with exercises for each phase, from initial injury to RTP.
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Affiliation(s)
- Xavier Valle
- Football Club Barcelona, Medical Department, Barcelona, Spain
- Corresponding author: Xavier Valle, Football Club Barcelona, Medical Department, Barcelona, Spain. Tel: +34-699416359, Fax: +34-934963664, E-mail:
| | | | - Bruce Hamilton
- Sports Medicine Department, Millenium Institute of Sport and Health, Auckland, New Zealand
| | - Gil Rodas
- Football Club Barcelona, Medical Department, Barcelona, Spain
| | - Peter Malliaras
- Sports Medicine Department, Centre for Sports and Exercise Medicine, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Nikos Malliaropoulos
- Sports Medicine Department, Centre for Sports and Exercise Medicine, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
- Musculoskeletal Department, Thessaloniki Sports Medicine Clinic, Thessaloniki, Greece
| | - Vicenc Rizo
- Football Club Barcelona, Medical Department, Barcelona, Spain
| | - Marcel Moreno
- Football Club Barcelona, Medical Department, Barcelona, Spain
| | - Jaume Jardi
- Football Club Barcelona, Medical Department, Barcelona, Spain
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Timmins RG, Shield AJ, Williams MD, Opar DA. Is There Evidence to Support the Use of the Angle of Peak Torque as a Marker of Hamstring Injury and Re-Injury Risk? Sports Med 2015; 46:7-13. [DOI: 10.1007/s40279-015-0378-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Abstract
Despite increased knowledge of hamstring muscle injuries, the incidence has not diminished. We now know that not all hamstring injuries are the same and that certain types of injuries require prolonged rehabilitation and return to play. The slow stretch type of injury and injuries involving the central tendon both require longer times to return to play. A number of factors have been proposed as being indicators of time taken to return to play, but the evidence for these is conflicting. Recurrence rates remain high and it is now thought that strength deficits may be an important factor. Strengthening exercise should be performed with the hamstrings in a lengthened position. There is conflicting evidence regarding the efficacy of platelet-rich plasma injection in the treatment of hamstring injuries so at this stage we cannot advise their use. Various tests have been proposed as predictors of hamstring injury and the use of the Nordboard is an interesting addition to the testing process. Prevention of these injuries is the ultimate aim and there is increasing evidence that Nordic hamstring exercises are effective in reducing the incidence.
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Arumugam A, Milosavljevic S, Woodley S, Sole G. Effects of external pelvic compression on isokinetic strength of the thigh muscles in sportsmen with and without hamstring injuries. J Sci Med Sport 2015; 18:283-8. [DOI: 10.1016/j.jsams.2014.05.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 05/07/2014] [Accepted: 05/17/2014] [Indexed: 10/25/2022]
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TIMMINS RYANG, SHIELD ANTHONYJ, WILLIAMS MORGAND, LORENZEN CHRISTIAN, OPAR DAVIDA. Biceps Femoris Long Head Architecture. Med Sci Sports Exerc 2015; 47:905-13. [DOI: 10.1249/mss.0000000000000507] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
Purpose:To evaluate the effect of simulated soccer on the hamstrings eccentric torque-angle profile and angle of peak torque (APTeccH), and on the hamstrings:quadriceps torque ratio at specific joint angles (ASHecc:Qcon).Methods:The authors assessed dominant-limb isokinetic concentric and eccentric knee flexion and concentric knee extension at 120°/s in 9 semiprofessional male soccer players immediately before and after they completed the Loughborough Intermittent Shuttle Test (LIST).Results:The LIST resulted in significant decreases in eccentric hamstrings torque at 60°, 50°, and 10° and a significant (21.8%) decrease in ASHecc:Qcon at 10° (P < .05). APTeccH increased from 7.1° ± 1.0° to 18.8° ± 4.2° (P < .05). Eccentric hamstrings peak torque significantly declined from 185.1 ± 70.4 N·m pre-LIST to 150.9 ± 58.5 N·m post-LIST (P = .002), but there were no significant changes in hamstrings or quadriceps concentric peak torque (P = .312, .169, respectively).Conclusions:Simulated soccer results in a selective loss of eccentric hamstrings torque and hamstrings-to-quadriceps muscle balance at an extended joint position and a shift in the eccentric hamstrings APT to a shorter length, changes that could increase vulnerability to hamstrings injury. These findings suggest that injury-risk screening could be improved by evaluating the eccentric hamstrings torque-angle profile and hamstrings strength-endurance and that the development of hamstrings fatigue resistance and long-length eccentric strength may reduce injury incidence.
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Sherry MA, Johnston TS, Heiderscheit BC. Rehabilitation of Acute Hamstring Strain Injuries. Clin Sports Med 2015; 34:263-84. [DOI: 10.1016/j.csm.2014.12.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Opar DA, Williams MD, Timmins RG, Hickey J, Duhig SJ, Shield AJ. The effect of previous hamstring strain injuries on the change in eccentric hamstring strength during preseason training in elite Australian footballers. Am J Sports Med 2015; 43:377-84. [PMID: 25398244 DOI: 10.1177/0363546514556638] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Hamstring strain injuries (HSIs) are the most common injury type in Australian football, and the rate of recurrence has been consistently high for a number of years. Long-lasting neuromuscular inhibition has been noted in previously injured athletes, but it is not known if this influences the athlete's adaptive response to training. PURPOSE To determine if elite Australian footballers with a prior unilateral HSI (previously injured group) display less improvement in eccentric hamstring strength during preseason training compared with athletes without a history of HSIs (control group). STUDY DESIGN Cohort study; Level of evidence, 2. METHODS A total of 99 elite Australian footballers (17 with a history of unilateral HSIs in the previous 12-month period) participated in this study. Eccentric hamstring strength was assessed at the start and end of preseason training using an instrumented Nordic hamstring device. The change in eccentric strength across the preseason was determined in absolute terms and normalized to the start of preseason strength. The start of preseason strength was used as a covariate to control for differences in starting strength. RESULTS The left and right limbs in the control group showed no difference in absolute or relative change (left limb: 60.7 ± 72.9 N and 1.28 ± 0.34 N, respectively; right limb: 48.6 ± 83.8 N and 1.24 ± 0.43 N, respectively). Similarly, the injured and uninjured limbs in the previously injured group showed no difference in either absolute or relative change (injured limb: 13.1 ± 57.7 N and 1.07 ± 0.18 N, respectively; uninjured limb: 14.7 ± 54.0 N and 1.07 ± 0.22 N, respectively). The previously injured group displayed significantly less increase in eccentric hamstring strength across the preseason (absolute change, 13.9 ± 55.0 N; relative change, 1.07 ± 0.20 N) compared with the control group (absolute change, 54.6 ± 78.5 N; relative change, 1.26 ± 0.39 N) for both absolute and relative measures (P < .001), even after controlling for differences in the start of preseason eccentric hamstring strength, which had a significant effect on strength improvement. CONCLUSION Elite Australian footballers with a unilateral history of HSIs displayed less improvement in eccentric hamstring strength across preseason training. The smaller improvements were not restricted to the previously injured limb as the contralateral limb also displayed similarly small improvements in eccentric strength. Whether this is the cause of or the result of an injury remains to be seen, but it has the potential to contribute to the risk of hamstring strain reinjuries.
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Affiliation(s)
- David A Opar
- School of Exercise Science, Australian Catholic University, Melbourne, Victoria, Australia
| | - Morgan D Williams
- Faculty of Health, Sport and Science, University of South Wales, Pontypridd, Wales, UK
| | - Ryan G Timmins
- School of Exercise Science, Australian Catholic University, Melbourne, Victoria, Australia
| | - Jack Hickey
- MD Health Pilates, Melbourne, Victoria, Australia
| | - Steven J Duhig
- School of Exercise and Nutrition Science, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Anthony J Shield
- School of Exercise and Nutrition Science, Queensland University of Technology, Brisbane, Queensland, Australia Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
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Mendiguchia J, Martinez-Ruiz E, Morin JB, Samozino P, Edouard P, Alcaraz PE, Esparza-Ros F, Mendez-Villanueva A. Effects of hamstring-emphasized neuromuscular training on strength and sprinting mechanics in football players. Scand J Med Sci Sports 2014; 25:e621-9. [PMID: 25556888 DOI: 10.1111/sms.12388] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/05/2014] [Indexed: 11/30/2022]
Abstract
The objective of this study was to examine the effects of a neuromuscular training program combining eccentric hamstring muscle strength, plyometrics, and free/resisted sprinting exercises on knee extensor/flexor muscle strength, sprinting performance, and horizontal mechanical properties of sprint running in football (soccer) players. Sixty footballers were randomly assigned to an experimental group (EG) or a control group (CG). Twenty-seven players completed the EG and 24 players the CG. Both groups performed regular football training while the EG performed also a neuromuscular training during a 7-week period. The EG showed a small increases in concentric quadriceps strength (ES = 0.38/0.58), a moderate to large increase in concentric (ES = 0.70/0.74) and eccentric (ES = 0.66/0.87) hamstring strength, and a small improvement in 5-m sprint performance (ES = 0.32). By contrast, the CG presented lower magnitude changes in quadriceps (ES = 0.04/0.29) and hamstring (ES = 0.27/0.34) concentric muscle strength and no changes in hamstring eccentric muscle strength (ES = -0.02/0.11). Thus, in contrast to the CG (ES = -0.27/0.14), the EG showed an almost certain increase in the hamstring/quadriceps strength functional ratio (ES = 0.32/0.75). Moreover, the CG showed small magnitude impairments in sprinting performance (ES = -0.35/-0.11). Horizontal mechanical properties of sprint running remained typically unchanged in both groups. These results indicate that a neuromuscular training program can induce positive hamstring strength and maintain sprinting performance, which might help in preventing hamstring strains in football players.
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Affiliation(s)
- J Mendiguchia
- Department of Physical Therapy, ZENTRUM Rehab and Performance Center, Barañain, Spain
| | - E Martinez-Ruiz
- Chair of Sports Traumatology, Catholic University of San Antonio, Murcia, Spain
| | - J B Morin
- Laboratory of Exercise Physiology, University of Saint-Etienne, Saint-Etienne, France
| | - P Samozino
- Laboratory of Exercise Physiology, University of Savoie, Le Bourget du Lac, France
| | - P Edouard
- Laboratory of Exercise Physiology, University of Saint-Etienne, Saint-Etienne, France.,Department of Physical Medicine and Rehabilitation, Saint-Etienne University Hospital, Saint-Etienne, France.,Laboratory of Exercise Physiology (EA 4338), University of Lyon, Lyon, France
| | - P E Alcaraz
- Research Center for High Performance Sport, Catholic University of San Antonio, Murcia, Spain
| | - F Esparza-Ros
- Chair of Sports Traumatology, Catholic University of San Antonio, Murcia, Spain
| | - A Mendez-Villanueva
- Aspire, Academy for Sports Excellence, Performance Enhancement and Talent Identification Section, Doha, Qatar
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Yu J. Comparison of Lower Limb Muscle Activity during Eccentric and Concentric Exercises in Runners with Achilles Tendinopathy. J Phys Ther Sci 2014; 26:1351-3. [PMID: 25276014 PMCID: PMC4175235 DOI: 10.1589/jpts.26.1351] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 02/27/2014] [Indexed: 11/24/2022] Open
Abstract
[Purpose] This study aimed to identify changes in muscle activation by comparing muscle activities of the affected side (AS) and non-affected side (NAS) during eccentric and concentric exercises in runners with unilateral Achilles tendinopathy. [Subjects] The study included 18 participants consisting of men and women with chronic Achilles tendinopathy in a single leg who had more than 1 year of running experience. [Methods] All subjects performed concentric and eccentric exercise with the Achilles tendon moving from full plantar flexion to full dorsiflexion for 8 seconds, and electromyography data was obtained. [Results] All muscles examined showed a significant increase in %maximal voluntary contraction (MVC) with concentric exercise compared with eccentric exercise. Compared with the NAS, the AS showed significant increases in %MVC of the rectus femoris, tibialis anterior, and lateral gastrocnemius. All interaction effects of exercise methods and injuries showed statistically significant changes. [Conclusion] Runners with Achilles tendinopathy show increases in medial gastrocnemius activity when performing eccentric exercise.
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Affiliation(s)
- Jaeho Yu
- Department of Physical Therapy, Sun Moon University, Republic of Korea
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Goossens L, Witvrouw E, Vanden Bossche L, De Clercq D. Lower eccentric hamstring strength and single leg hop for distance predict hamstring injury in PETE students. Eur J Sport Sci 2014; 15:436-42. [DOI: 10.1080/17461391.2014.955127] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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63
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Opar DA, Serpell BG. Is There a Potential Relationship Between Prior Hamstring Strain Injury and Increased Risk for Future Anterior Cruciate Ligament Injury? Arch Phys Med Rehabil 2014; 95:401-5. [DOI: 10.1016/j.apmr.2013.07.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 07/30/2013] [Indexed: 10/26/2022]
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Sanfilippo JL, Silder A, Sherry MA, Tuite MJ, Heiderscheit BC. Hamstring strength and morphology progression after return to sport from injury. Med Sci Sports Exerc 2013; 45:448-54. [PMID: 23059864 DOI: 10.1249/mss.0b013e3182776eff] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE Hamstring strain reinjury rates can reach 30% within the initial 2 wk after return to sport (RTS). Incomplete recovery of strength may be a contributing factor. However, relative strength of the injured and unaffected limbs at RTS is currently unknown.The purpose was to characterize hamstring strength and morphology at the time of RTS and 6 months later. METHODS Twenty-five athletes who experienced an acute hamstring strain injury participated after completion of a controlled rehabilitation program. Bilateral isokinetic strength testing and magnetic resonance imaging (MRI) were performed at RTS and 6 months later. Strength (knee flexion peak torque, work, and angle of peak torque) and MRI (muscle and tendon volumes) measures were compared between limbs and over time using repeated-measures ANOVA. RESULTS The injured limb showed a peak torque deficit of 9.6% compared to the uninjured limb at RTS (60°·s, P < 0.001) but not 6 months after. The knee flexion angle of peak torque decreased over time for both limbs (60°·s, P < 0.001). MRI revealed that 20.4% of the muscle cross-sectional area showed signs of edema at RTS with full resolution by the 6-month follow-up. Tendon volume of the injured limb tended to increase over time (P = 0.108), whereas muscle volume decreased between 4% and 5% in both limbs (P < 0.001). CONCLUSIONS Residual edema and deficits in isokinetic knee flexion strength were present at RTS but resolved during the subsequent 6 months. This occurred despite MRI evidence of scar tissue formation (increased tendon volume) and muscle atrophy, suggesting that neuromuscular factors may contribute to the return of strength.
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Affiliation(s)
- Jennifer L Sanfilippo
- Departments of Biomedical Engineering and Athletics University of Wisconsin-Madison, Madison, WI, USA
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Opar DA, Williams MD, Timmins RG, Dear NM, Shield AJ. Knee flexor strength and bicep femoris electromyographical activity is lower in previously strained hamstrings. J Electromyogr Kinesiol 2013; 23:696-703. [DOI: 10.1016/j.jelekin.2012.11.004] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 10/22/2012] [Accepted: 11/06/2012] [Indexed: 11/16/2022] Open
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The role of neuromuscular inhibition in hamstring strain injury recurrence. J Electromyogr Kinesiol 2013; 23:523-30. [DOI: 10.1016/j.jelekin.2012.12.006] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 11/29/2012] [Accepted: 12/14/2012] [Indexed: 11/22/2022] Open
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Askling CM, Tengvar M, Thorstensson A. Acute hamstring injuries in Swedish elite football: a prospective randomised controlled clinical trial comparing two rehabilitation protocols. Br J Sports Med 2013; 47:953-9. [DOI: 10.1136/bjsports-2013-092165] [Citation(s) in RCA: 152] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Brukner P, Nealon A, Morgan C, Burgess D, Dunn A. Recurrent hamstring muscle injury: applying the limited evidence in the professional football setting with a seven-point programme. Br J Sports Med 2013; 48:929-38. [PMID: 23322894 PMCID: PMC4033203 DOI: 10.1136/bjsports-2012-091400] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Recurrent hamstring injuries are a major problem in sports such as football. The aim of this paper was to use a clinical example to describe a treatment strategy for the management of recurrent hamstring injuries and examine the evidence for each intervention. A professional footballer sustained five hamstring injuries in a relatively short period of time. The injury was managed successfully with a seven-point programme—biomechanical assessment and correction, neurodynamics, core stability, eccentric strengthening, an overload running programme, injection therapies and stretching/relaxation. The evidence for each of these treatment options is reviewed. It is impossible to be definite about which aspects of the programme contributed to a successful outcome. Only limited evidence is available in most cases; therefore, decisions regarding the use of different treatment modalities must be made by using a combination of clinical experience and research evidence.
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Affiliation(s)
- Peter Brukner
- Departmernt of Sports Medicine and Sports Science, Liverpool Football Club, , Liverpool, UK
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69
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Opar DA, Williams MD, Timmins RG, Dear NM, Shield AJ. Rate of torque and electromyographic development during anticipated eccentric contraction is lower in previously strained hamstrings. Am J Sports Med 2013; 41:116-25. [PMID: 23108640 DOI: 10.1177/0363546512462809] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND The effect of prior strain injury on myoelectrical activity of the hamstrings during tasks requiring high rates of torque development has received little attention. PURPOSE To determine if recreational athletes with a history of unilateral hamstring strain injury will exhibit lower levels of myoelectrical activity during eccentric contraction, rate of torque development (RTD), and impulse (IMP) at 30, 50, and 100 milliseconds after the onset of myoelectrical activity or torque development in the previously injured limb compared with the uninjured limb. STUDY DESIGN Case control study; Level of evidence, 3. METHODS Twenty-six recreational athletes were recruited. Of these, 13 athletes had a history of unilateral hamstring strain injury (all confined to biceps femoris long head), and 13 had no history of hamstring strain injury. Following familiarization, all athletes undertook isokinetic dynamometry testing and surface electromyography (integrated EMG; iEMG) assessment of the biceps femoris long head and medial hamstrings during eccentric contractions at -60 and -180 deg·s(-1). RESULTS In the injured limb of the injured group, compared with the contralateral uninjured limb, RTD and IMP was lower during -60 deg·s(-1) eccentric contractions at 50 milliseconds (RTD: injured limb, 312.27 ± 191.78 N·m·s(-1) vs uninjured limb, 518.54 ± 172.81 N·m·s(-1), P = .008; IMP: injured limb, 0.73 ± 0.30 N·m·s vs uninjured limb, 0.97 ± 0.23 N·m·s, P = .005) and 100 milliseconds (RTD: injured limb, 280.03 ± 131.42 N·m·s(-1) vs uninjured limb, 460.54 ± 152.94 N·m·s(-1), P = .001; IMP: injured limb, 2.15 ± 0.89 N·m·s vs uninjured limb, 3.07 ± 0.63 N·m·s, P < .001) after the onset of contraction. Biceps femoris long head muscle activation was lower at 100 milliseconds at both contraction speeds (-60 deg·s(-1), normalized iEMG activity [×1000]: injured limb, 26.25 ± 10.11 vs uninjured limb, 33.57 ± 8.29, P = .009; -180 deg·s(-1), normalized iEMG activity [×1000]: injured limb, 31.16 ± 10.01 vs uninjured limb, 39.64 ± 8.36, P = .009). Medial hamstring activation did not differ between limbs in the injured group. Comparisons in the uninjured group showed no significant between limbs difference for any variables. CONCLUSION Previously injured hamstrings displayed lower RTD and IMP during slow maximal eccentric contraction compared with the contralateral uninjured limb. Lower myoelectrical activity was confined to the biceps femoris long head. Regardless of whether these deficits are the cause of or the result of injury, these findings could have important implications for hamstring strain injury and reinjury. Particularly, given the importance of high levels of muscle activity to bring about specific muscular adaptations, lower levels of myoelectrical activity may limit the adaptive response to rehabilitation interventions and suggest that greater attention be given to neural function of the knee flexors after hamstring strain injury.
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Affiliation(s)
- David A Opar
- School of Exercise and Nutrition Science, Queensland University of Technology, Brisbane, Australia.
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Abstract
Hamstring muscle injuries are a frequent cause of athletic sequelae, and the frequency of reinjuries is high. Frequently, disability in sport is the consequence and performance is limited. A case report of a soccer player who was unable to play his sport after a minor hamstring muscle injury is presented. We introduce a previously undescribed lesion featured by a scar compromising a motor branch of the sciatic nerve to the long head of the biceps femoris muscle. Resection of the involved branch of the nerve resulted in complete pain relief and full sport capacity. This case report demonstrates that in very rare cases, a scar tissue-induced intramuscular entrapment of a branch of the sciatic nerve must be considered as a reason for athletic incapacity after minor hamstring injury. Both the degree of a muscular injury and its specific location within the injured muscle may therefore influence the functional outcome.
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Arumugam A, Milosavljevic S, Woodley S, Sole G. Can application of a pelvic belt change injured hamstring muscle activity? Med Hypotheses 2012; 78:277-82. [PMID: 22169627 DOI: 10.1016/j.mehy.2011.10.045] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 10/27/2011] [Indexed: 11/17/2022]
Affiliation(s)
- Ashokan Arumugam
- Centre for Physiotherapy Research, School of Physiotherapy, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
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