Review
The role of neuromuscular inhibition in hamstring strain injury recurrence

https://doi.org/10.1016/j.jelekin.2012.12.006Get rights and content

Abstract

Hamstring strain injuries are amongst the most common and problematic injuries in a wide range of sports that involve high speed running. The comparatively high rate of hamstring injury recurrence is arguably the most concerning aspect of these injuries. A number of modifiable and nonmodifiable risk factors are proposed to predispose athletes to hamstring strains. Potentially, the persistence of risk factors and the development of maladaptations following injury may explain injury recurrence. Here, the role of neuromuscular inhibition following injury is discussed as a potential mechanism for several maladaptations associated with hamstring re-injury. These maladaptations include eccentric hamstring weakness, selective hamstring atrophy and shifts in the knee flexor torque-joint angle relationship. Current evidence indicates that athletes return to competition after hamstring injury having developed maladaptations that predispose them to further injury. When rehabilitating athletes to return to competition following hamstring strain injury, the role of neuromuscular inhibition in re-injury should be considered.

Introduction

Hamstring strains are amongst the most common and problematic injuries in a wide range of sports that involve high speed running. They are the primary injury in Australian football (Gabbe et al., 2002, Orchard and Seward, 2002, Orchard and Seward, 2009, Orchard and Seward, 2010, Seward et al., 1993), soccer (Ekstrand and Gillquist, 1983, Ekstrand et al., 2010, Hawkins et al., 2001, Woods et al., 2002, Woods et al., 2004) and the sprint events in track & field (Drezner et al., 2005, Sugiura et al., 2008, Yeung et al., 2009), while also accounting for a high proportion of lost playing time in cricket (Orchard and James, 2003, Orchard et al., 2002, Stretch, 2003), rugby union (Brooks et al., 2005a, Brooks et al., 2005b, Brooks et al., 2005c, Brooks et al., 2006), Gaelic football (Newell et al., 2006, O’Sullivan et al., 2008), American football (Elliott et al., 2011, Feeley et al., 2008, Meeuwisse et al., 2000) and hurling (Murphy et al., 2010).

High rates of injury recurrence are arguably the most troublesome aspect of hamstring strains because recurring injuries often result in substantially more lost playing time than the original insults (Brooks et al., 2006, Ekstrand et al., 2011, Koulouris et al., 2007) and because the hamstrings remain at elevated risk of injury recurrence for longer than other strained muscles (Orchard and Best, 2002). There is also evidence for a significant rate of recurrence across consecutive seasons (Carling et al., 2011, Hagglund et al., 2006, Verrall et al., 2006). Hamstring strain recurrence rates of 16–60% have been reported in American football (Elliott et al., 2011, Heiser et al., 1984), rugby union (Brooks et al., 2006), soccer (Ekstrand et al., 2011), the sprint events in track and field (Drezner et al., 2005, Yeung et al., 2009) and in Australian football (Orchard and Seward, 2010). A long-term program of compulsory injury reporting in the Australian Football League (AFL) indicates that same-season hamstring re-injury rates have averaged 23% in the last 10 seasons (Orchard and Seward, 2010). However, this figure almost certainly underestimates true recurrence rates as it does not take into account lost pre-season training time.

Statistics on first and recurrent hamstring strain injuries indicate that injury prevention and rehabilitation practices are not as effective as athletes and coaches would like them to be. We argue that the current understanding of injury risk factors is inadequate and that neuromuscular inhibition of the hamstrings, previously ignored in literature and underemphasised in rehabilitation programs, may at least partially explain high hamstring injury recurrence rates. The objectives of this review article are to (i) discuss factors relating to hamstring strain injury recurrence and (ii) discuss the potential role of neuromuscular inhibition in these recurrences.

Section snippets

The persistence of risk factors

A number of modifiable and non-modifiable risk factors are proposed to predispose athletes to hamstring strains (Copeland et al., 2009, Croisier, 2004a, Devlin, 2000, Opar et al., 2012a). Modifiable factors include hamstring weakness (Croisier et al., 2008, Orchard et al., 1997, Sugiura et al., 2008, Yeung et al., 2009), poor flexibility (Bradley and Portas, 2007, Witvrouw et al., 2003) and fatigue (Brooks et al., 2006, Ekstrand et al., 2011, Woods et al., 2004), while the non-modifiable

Is rehabilitation sabotaged by neuromuscular inhibition?

The following section discusses the putative role of neuromuscular inhibition in hamstring strain injury recurrence (Opar et al., 2012a). A conceptual framework for the proposed relationship between neuromuscular inhibition and several maladaptations associated with hamstring strain injury recurrence is shown in Fig. 2.

The early stages of conventional hamstring rehabilitation are characterised by the avoidance of excessive muscle stretch, initially because stretch may exacerbate scar formation (

Conclusion

The persistence of risk factors and the development of maladaptations following hamstring strain injury may explain injury recurrence. Several post-hamstring injury maladaptations have been identified in the literature, which, if not specifically addressed during rehabilitation, potentially contribute to injury recurrence. It is proposed that pain-driven neuromuscular inhibition of hamstring voluntary activation occurs following hamstring strain injury, and that this inhibition has a

Conflict of interest

None declared.

Acknowledgements

No external contributors were involved nor was any financial assistance provided for the completion of this project.

Jackson Fyfe completed his Bachelor of Exercise Science (Hons) at Australian Catholic University in Melbourne, Australia investigating chronic neuromuscular inhibition following hamstring strain injury. He is currently undertaking his PhD within the College of Sport and Exercise Science at Victoria University, Melbourne, Australia.

References (124)

  • R.W. Paton et al.

    Biomechanical assessment of the effects of significant hamstring injury: an isokinetic study

    J Biomech Eng

    (1989)
  • D.A. Rice et al.

    Quadriceps arthrogenic muscle inhibition: neural mechanisms and treatment perspectives

    Semin Arthritis Rheum

    (2010)
  • A.G. Schache et al.

    Biomechanical response to hamstring muscle strain injury

    Gait Posture

    (2009)
  • A. Silder et al.

    The influence of prior hamstring injury on lengthening muscle tissue mechanics

    J Biomech

    (2010)
  • A. Arnason et al.

    Prevention of hamstring strains in elite soccer: an intervention study

    Scand J Med Sci Sports

    (2008)
  • A. Arnason et al.

    Risk factors for injuries in football

    Am J Sports Med

    (2004)
  • C. Askling et al.

    Acute first-time hamstring strains during high-speed running: a longitudinal study including clinical and magnetic resonance imaging findings

    Am J Sports Med

    (2007)
  • R. Bahr et al.

    Risk factors for sports injuries–a methodological approach

    Br J Sports Med

    (2003)
  • D.G. Behm et al.

    Fatigue characteristics following ankle fractures

    Med Sci Sports Exerc

    (1997)
  • K. Bennell et al.

    Isokinetic strength testing does not predict hamstring injury in Australian Rules footballers

    Br J Sports Med

    (1998)
  • P.S. Bradley et al.

    The relationship between preseason range of motion and muscle strain injury in elite soccer players

    J Strength Condition Res

    (2007)
  • C.L. Brockett et al.

    Human hamstring muscles adapt to eccentric exercise by changing optimum length

    Med Sci Sports Exerc

    (2001)
  • C.L. Brockett et al.

    Predicting hamstring strain injury in elite athletes

    Med Sci Sports Exerc

    (2004)
  • J.H. Brooks et al.

    A prospective study of injuries and training amongst the England 2003 Rugby World Cup squad

    Br J Sports Med

    (2005)
  • J.H. Brooks et al.

    Epidemiology of injuries in English professional rugby union: part 1 match injuries

    Br J Sports Med

    (2005)
  • J.H. Brooks et al.

    Epidemiology of injuries in English professional rugby union: part 2 training Injuries

    Br J Sports Med

    (2005)
  • J.H. Brooks et al.

    Incidence, risk, and prevention of hamstring muscle injuries in professional rugby union

    Am J Sports Med

    (2006)
  • T.A. Butterfield et al.

    The magnitude of muscle strain does not influence serial sarcomere number adaptations following eccentric exercise

    Eur J Appl Physiol

    (2006)
  • C. Carling et al.

    A four-season prospective study of muscle strain reoccurrences in a professional football club

    Res Sports Med

    (2011)
  • E.S. Chumanov et al.

    Hamstring musculotendon dynamics during stance and swing phases of high-speed running

    Med Sci Sports Exerc

    (2011)
  • S.T. Copeland et al.

    Evidence-based treatment of hamstring tears

    Curr Sports Med Rep

    (2009)
  • J.-L. Croisier

    Factors associated with recurrent hamstring injuries

    Sports Med

    (2004)
  • J.-L. Croisier

    Muscular imbalance and acute lower extremity muscle injuries in sport

    Int Sports Med J

    (2004)
  • J.-L. Croisier et al.

    Hamstring muscle tear with recurrent complaints: an isokinetic profile

    Isokin Exer Sci

    (2000)
  • J.-L. Croisier et al.

    Hamstring muscle strain recurrence and strength performance disorders

    Am J Sports Med

    (2002)
  • J.-L. Croisier et al.

    Strength imbalances and prevention of hamstring injury in professional soccer players: a prospective study

    Am J Sports Med

    (2008)
  • M. Dauty et al.

    Identification of previous hamstring muscle injury by isokinetic concentric and eccentric torque measurement in elite soccer player

    Isokinet Exer Sci

    (2003)
  • L. Devlin

    Recurrent posterior thigh symptoms detrimental to performance in rugby union: predisposing factors

    Sports Med

    (2000)
  • L.P. Diederichsen et al.

    The influence of experimentally induced pain on shoulder muscle activity

    Exp Brain Res

    (2009)
  • J.A. Drezner

    Practical management: hamstring muscle injuries

    Clin J Sports Med

    (2003)
  • J.A. Drezner et al.

    Hamstring muscle injuries in track and field athletes: a 3-year study at the Penn Relay Carnival [abstract]

    Clin J Sports Med

    (2005)
  • J. Ekstrand et al.

    Soccer injuries and their mechanisms: a prospective study

    Med Sci Sports Exerc

    (1983)
  • Ekstrand J, Hagglund M, Walden M. Injury incidence and injury patterns in professional football – the UEFA injury...
  • J. Ekstrand et al.

    Epidemiology of muscle injuries in professional football (soccer)

    Am J Sports Med

    (2011)
  • M.C. Elliott et al.

    Hamstring muscle strains in professional football players: a 10-year review

    Am J Sports Med

    (2011)
  • A.H. Engebretsen et al.

    Prevention of injuries among male soccer players: a prospective, randomized intervention study targeting players with previous injuries or reduced function

    Am J Sports Med

    (2008)
  • B.T. Feeley et al.

    Epidemiology of National Football League training camp injuries from 1998 to 2007

    Am J Sports Med

    (2008)
  • B.J. Gabbe et al.

    Predictors of hamstring injury at the elite level of Australian football

    Scand J Med Sci Sports

    (2006)
  • B.J. Gabbe et al.

    Risk factors for hamstring injuries in community level Australian football

    Br J Sports Med

    (2005)
  • W.E. Garrett et al.

    Biomechanical comparison of stimulated and nonstimulated skeletal muscle pulled to failure

    Am J Sports Med

    (1987)
  • Cited by (121)

    • Hamstring and ACL injuries impacts on hamstring-to-quadriceps ratio of the elite soccer players: A retrospective study

      2022, Physical Therapy in Sport
      Citation Excerpt :

      Athletes from other sports can have different thigh muscle strength ratio compared to soccer players, which makes the comparison difficult (Magalhaes, Ascensao, & Soares, 2004). Hamstring inhibition due to injury could be one mechanism for the reduction in NAS H:Q values (Fyfe, Opar, Williams, & Shield, 2013). Previously injured hamstring has shown to have reduced muscle activation which could potentially result in lower torque production (Opar, Williams, Timmins, Dear, & Shield, 2013).

    View all citing articles on Scopus

    Jackson Fyfe completed his Bachelor of Exercise Science (Hons) at Australian Catholic University in Melbourne, Australia investigating chronic neuromuscular inhibition following hamstring strain injury. He is currently undertaking his PhD within the College of Sport and Exercise Science at Victoria University, Melbourne, Australia.

    David Opar completed his B. App. Sci (HM) (Hons) at RMIT University, Melbourne, Australia and completed his PhD at Queensland University of Technology, Queensland, Australia. His thesis, supervised by Dr. Anthony Shield and Dr. Morgan Williams, focused on alterations to neuromuscular hamstring function in previously injured athletes. Currently he is a Lecturer in Exercise Science at Australian Catholic University, Melbourne, Australia.

    Morgan Williams completed a PhD at ACU in Melbourne, Australia. He is currently a Senior Lecturer in Sports Science at the University of Glamorgan, Wales, UK.

    Anthony Shield has an interest in the applications of eccentric exercise with a current focus on hamstring strain injury. He completed his PhD at Southern Cross University, Australia and is currently a Senior Lecturer in the School of Exercise and Nutrition Sciences at Queensland University of Technology.

    View full text