Written by Roald Bahr and Nicol van Dyk, Qatar
Category: Sports Science

Volume 8 | Targeted Topic – Hamstring Injuries - Aspetar Experience | 2019
Volume 8 - Targeted Topic – Hamstring Injuries - Aspetar Experience



– Written by Roald Bahr and Nicol van Dyk, Qatar



Hamstring injuries represent a substantial injury burden in football1, and is the most common non-contact muscle injury overall2. It has been demonstrated that player availability impacts negatively on team success3-5, and therefore the management of hamstring injuries continue to receive much attention in the literature6-8, as well as the mainstream media. However, injury prevention efforts have not reduced the number of injuries at the elite level. Incidence patterns in the UEFA Champions League have demonstrated a steady increase of 2.3% in the hamstring injury rate per year, at least until 20149. These results are worrying, considering that investigations identifying risk factors associated with these injuries have been plentiful10-12. Unfortunately, these studies continue to provide contrasting conclusions, often directly contradicting each other’s findings. This is evident in systematic reviews that do not provide substantial evidence for any specific, modifiable risk factor10-12.

In this report, we highlight some of the recent risk factor findings in the larger context of injury prevention. We consider what clinical implications these findings might hold and make recommendations for clinical practice.



A number of intervention studies have shown to be effective at reducing hamstring injuries; the greatest effect found in studies focused on eccentric strengthening6,7,13. Although not specifically aimed at hamstring injuries, similar success was observed where the intervention was aimed at neuromuscular function and improving flexibility3,14,15. There are perceptions and beliefs around these prevention strategies, from the players regarding soreness or the coaching staff regarding usefulness, that pose serious barriers to implementation16,17. These issues are important to address if we are to have success in implementing prevention programmes in the real world. However, there seems to be a “disconnect” between the identification of risk factors associated with hamstring injury, and the results of injury prevention studies.



Age, ethnicity, and playing position

Age is consistently identified as a risk factor for hamstring injury. It is not clear why older players are at greater risk of injury12,18,19. Some theories have been suggested, such as loss of muscle mass leading to decreased strength, and changes in muscle structure. Arnason et al did not find a mediating effect of previous injury on age, confirming an independent relationship between age and risk of hamstring injury20. However, in a separate investigation, the risk associated with increased age was mitigated by improvements in eccentric strength21, suggesting that the interaction between these two risk factors, one modifiable and the other non-modifiable, may be important.

Recent studies from large investigations on risk factors from the Arabic peninsula did not find ethnicity to be associated with an increased risk of hamstring injury18,22,23. The role of ethnicity and how it may impact injury risk is still poorly understood24.

Predictably, goalkeepers are much less likely to sustain a hamstring injury when compared to outfielders. High speed running is considered the predominant hamstring injury mechanism involved in football, and outfielders are naturally required to do much more running compared to goalkeepers25,26.


Previous injury is not associated with risk of injury... wait, what?

A history of previous injury has been identified as a risk factor for hamstring injury11,12,20,27. Hamilton et al explores two potential theories to explain the relationship between previous injury and subsequent injury28. Firstly, a causal relationship exists between previous injury and future risk of injury, most likely due to inadequate rehabilitation. This might lead to incomplete healing, weakness of the previously injured tissue, and other possible functional movement or even psychological factors that persist after return to sport28. Alternatively, a “no causal marker” theory is proposed, where previous injury is simply a marker for other factors that would cause an individual to be at greater risk of injury. This would suggest that confounding bias is present when a history of previous injury is examined as a potential risk factor.

Recent investigations from Qatar provide some interesting results. Previous injury was found to be a risk factor in the first study over a four-year period. However, during the subsequent two seasons, previous injury was not found to be associated with an increased risk of hamstring injury.

To interpret these contrasting results, let us consider the context of this investigation. Two large randomised control trials (RCT) were being conducted at the Aspetar Orthopaedic and Sports Medicine Hospital during this period. Both studies incorporated a structured criteria-based rehabilitation programme and included a large number of football players. While the second RCT is currently being concluded, the first RCT reported a 12-month re-injury rate of 6%29,30, which is low compared to reports from other football populations31. If we consider previous injury a “no causal marker” for other predisposing factors, present in certain individuals, our finding suggest that the introduction of a systematic, criteria based rehabilitation programme may have reduced the risk associated with previous injury by addressing some of these factors. Alternatively, if we assume that a causal relationship exists between previous injury and subsequent hamstring injury, the player may have received adequate rehabilitation, including optimal loading and criteria-based progression to address predisposing risk factors32,33. Either way, this study did not aim to measure the effect of a rehabilitation programme for hamstring injuries on the risk of subsequent injury. However, in this cohort, with the study centre being the focal point of care for the entire football league, it seems a plausible explanation. Such an effect has also been observed in volleyball, where the association between previous injury and ankle sprains was no longer identified after the implementation of a structured rehabilitation programme34.



Strength – an oldie but a goodie?

Isokinetic dynamometer strength testing is still considered a reliable measure of determining the strength profile of individual players35. At the elite level, coaches and medical staff rely heavily on isokinetic testing, often making recommendations for training or rehabilitation based on the results of these tests17,36,37. Previous prospective studies have investigated a host of measures derived from these tests, including peak torque, both as an absolute value and normalised to bodyweight, leading to contradicting results12.

In a comprehensive isokinetic strength assessment in the largest cohort of football players to date, a significant association was found between lower concentric quadriceps and eccentric hamstring strength, normalised to bodyweight, at slow speed18. Confirming the results from previous meta-analysis12, another large prospective cohort study indicated that greater quadriceps strength was associated with an increased risk of hamstring injury22.

The findings in both our studies indicate that there is a relationship, albeit weak, between strength and risk of hamstring injury.


Ratios – an imperfect solution

In addition to peak strength measures, different strength ratios have received much attention in the literature, in particular the hamstrings to quadriceps (H:Q) ratio12,38-40. Interestingly, there is inconsistency in identifying the H:Q ratio as a risk factor for hamstring injury, as observed in the meta-analysis by Freckleton and Pizzari12. Several candidate H:Q ratios, both conventional and dynamic entities of mixed isokinetic strength, had no association with subsequent injury.

There has been some debate over how these ratios are interpreted statistically41. A ratio assumes that the slope of the relationship between the logarithmically-transformed numerator and denominator is one. If this assumption is violated, then the ratio will scale inaccurately at the lower and higher ends of the range measured, leading to errors in interpretation. Also, when normally distributed variables are divided by each other, it is unlikely that the resulting ratio is normally distributed itself41.


Nordic hamstring exercise – does it deserve the attention it’s getting?

Nordic hamstring exercise, performed as a screening test, was previously dichotomised into a pass/fail result based on range of motion, it was not identified as a risk factor for injury42. With the subsequent development of a novel testing device, the eccentric force produced during the test was made measureable43. The novel test device has been used in preseason Nordic hamstring exercise strength assessments in football and Australian football, with these studies reporting players with lower eccentric strength during the Nordic hamstring exercise being more likely to suffer a hamstring injury21,44. In these studies, other potential effect modifiers, such as previous injury, age and biceps femoris fascicle length, were included in a multifactorial model, but did not markedly improve the association between limb strength imbalances with risk of hamstring injury45. However, considering that these studies identified increased risk of injury with eccentric strength measured during the Nordic hamstring exercise, it highlights the importance of validating these risk factors in different cohorts45.

The use of the Nordic hamstring exercise in intervention programmes has been successful, and we do not contest that the Nordic hamstring strength test may be a useful tool to the clinician. In fact, it has arguably been shown as the most effective intervention tool to reduce the incidence of hamstring injuries in football6,7,20. In the clinical context, it might still be useful to perform the Nordic hamstring strength test to determine a baseline before implementing a specific eccentric strength training programme. However, in a large middle east cohort, eccentric hamstring strength measured during the Nordic hamstring exercise was not identified as risk factor for hamstring injury.


Flexibility of the posterior thigh and ankle

Two studies have reported a significant association between hamstring flexibility and injury, measured with the supine straight leg raise test15,46. In contrast, studies that measured flexibility using the active and passive knee extension test did report an association20,42,47. The sit-and-reach test has also been used to determine hamstring flexibility, with no association between hamstring flexibility and risk of hamstring injury48. Measures other than the tests that measure posterior thigh flexibility have also been suggested as potential risk factors49,50. The dorsiflexion lunge test, measuring ankle range of motion, has been investigated previously49. A recent meta-analysis reported conflicting evidence for the ankle dorsiflexion lunge test12. However, both passive knee extension and ankle dorsiflexion range of motion have demonstrated a significant association with increased risk of hamstring injury19. Interestingly, both these tests represent range of motion changes in the posterior kinetic chain.


The relationship between intrinsic neuromuscular function and risk of hamstring injury

It is difficult to encapsulate all the components necessary for optimal neuromuscular function in one single test, or even a combination of variables. Recent investigations into the lumbo-pelvic-hip complex suggest that the neuromuscular coordination in the posterior kinetic chain influences the risk of hamstring injury in male football players61. This suggests a protective effect if the global musculature is addressed in terms of neuromuscular function51,52. In the first investigation of intrinsic neuromuscular function pre-injury, neither rate of torque development nor the onset of muscle activity for any of the concentric or eccentric quadriceps and hamstring isokinetic modes of testing were associated with risk of hamstring injury. Considering previous findings, differences in rate of torque development and muscle activity32 are most likely the consequence of the injury, and both these variables may be altered post-injury. Previous findings suggest that insufficient capacity to generate force (altered rate of torque development) and delayed muscle activity during the early phase of the movement may represent a reduction in ‘early neural drive’, indicating altered neuromuscular function53,54. These differences post-injury might be expected to influence the stimulus needed to induce muscle hypertrophy and sarcomerogenesis, predominantly during eccentric contraction, needed for adequate rehabilitation53. It is important to acknowledge that these measures only represent one aspect of intrinsic neuromuscular function.

Fyfe et al has suggested a conceptual framework where neuromuscular inhibition persists after hamstring injury, therefore sabotaging the rehabilitation process, leading to several maladaptations, poor outcomes, and elevated risk of re-injury55. General consensus regarding return to play criteria after hamstring injury do not include an assessment of neuromuscular function7,56. In fact, due to the difficulty in defining and assessing neuromuscular function, it was specifically excluded from one of the consensus statements57. It raises two questions - are we addressing neuromuscular function appropriately in our rehabilitation? And secondly, should the player that has suffered a hamstring injury continue to receive training focused on resolving neuromuscular inhibition even after return to play?


Workload – the new kid on the block?

Emerging evidence supports the clinical hypothesis that the amount of training and competition undertaken is related to the incidence of injuries and illnesses in competitive athletes58-60. However, to date, investigations into the relationship between workload and injury have been limited to small sample sizes, with inconsistencies in the variables reported to have a significant association with injury.

A potential modifiable hamstring injury risk is workload (training and match load undertaken by the players). In the past ten years, the number of publications investigating the relationship between training and injury has increased four-fold; yet, our ability to appropriately quantify this relationship is still poorly understood.



Injury prediction vs risk factor identification

The purpose of any screening strategy is the early detection of pathology or disease (usually in a symptom free population) to allow appropriate and early intervention which hopefully leads to prevention of the pathology, and reduces the morbidity and mortality45. In sports medicine, we have adopted this strategy from general medicine, aimed at addressing risk factors to prevent injury. But it seems the interpretation of risk identification has been “lost in translation” in sports medicine. One purpose of the periodic health evaluation (screening) may indeed be to identify risk factors present in individuals that may allow early targeted intervention and prevent injury. However, as demonstrated in Figure 1, even if the group average differs, the distribution of injured and uninjured players completely overlap. We might then question the value of screening, and ask if we can still make meaningful conclusions from the information we collect during the screening process.


Is screening a waste of time?

Co-investigations were performed at the Aspetar Orthopaedic and Sports Medicine Hospital aimed to determine whether screening is useful to identify risk factors for hamstring injury, hip and groin injury, as well as the predictive value of functional movement screening (FMS)62,63. Overall, none of these studies provided any screening test with high predictive value and cannot identify players at high risk of injury successfully. The large variability we identified between seasons in tests results, together with similar distribution of injured and uninjured players emphasise the lack of clinical utility in the current tests used to screen for risk of injury.

However, significant group findings of certain variables associated with increased risk of injury were identified. These findings might assist in how we design our prevention programmes, specifically which factors to include in a multifactorial injury prevention model. Verhagen et al uses the example of previous injury to demonstrate how we may find meaning in identifying at risk players, where the risk interpretation is different for players with a history of previous injury68.


A complex and temporal problem

Prospective cohort studies are aimed at identifying certain risk factors associated with injury, thus “explaining” the injury by identifying its cause. Rothman describes a cause as an inciting event - either in isolation or in conjunction with other events - that initiates or allows a sequence of events which results in an effect (i.e. hamstring injury)64. A cause which inevitably produces an effect is described as sufficient. Our findings suggest that both strength and flexibility are perhaps components in a larger sufficient cause of hamstring injury. Therefore, by addressing one component needed to produce a sufficient cause for hamstring injury it is, at least theoretically, possible that the intervention could prevent the injury from occurring.

However, these programmes aimed at one of the identified risk factors are often not adapted in practice16. Recently, the context (and complexity) that underly the implementation of prevention programmes has been emphasised (Figure 2)65. It is important that we include these components when we plan our prevention strategies. Without it, successful adoption of the intervention remains unlikely.

Clinically, it is likely that the strength of players will change in response to team training and individual strengthening regimens. Risk factors are time-based, and we observe substantial temporal variability. In most prospective risk factor studies, the risk factor identification was determined during a pre-season screening examination, and the players were followed for the subsequent season. Unfortunately, we do not monitor how the factors we measure change over time, and therefore our analyses are based on the assumption that our screening results are “frozen-in-time”; representative of that factor at the time of injury. The investigation into the stability of these tests support our clinical intuition, that there is substantial variability in these measurements over time. It provides motivation to move away from isolated time-point testing towards continuous monitoring of these risk factors, allowing the clinician to identify changes in these risk factors, and how these changes might be associated with risk of injury. The template for this type of monitoring has been provided in overuse injuries focused around injury burden rather than time loss due to injury66, yet the hypothesis of monitoring risk factors as an alternative to once-off screening has not been investigated. As injury risk is influenced by workload67, we might expect that strength and other factors would be affected. However, we have yet to establish a better understanding of the interactions between these factors, and how these factors may respond to different fluctuation in applied load over time.



To assist the clinician with translating this information into clinical practice, we have summarised the findings.  The five key points are:

  1. Strength and Flexibility are weak risk factors for hamstring injuries and continue to form a small but important part of the causal pathway. Although the evidence for stretching is lacking, multi-faceted prevention programmes might consider including these components to be successful in the prevention of hamstring injuries.
  2. Intrinsic neuromuscular function may be altered post-injury. Clinicians should focus on returning the player to full function during the rehabilitation of hamstring injuries, which may include specific targeted intervention even after return to play.
  3. Our common strength and flexibility tests have poor predictive value, and do not possess the characteristics needed to successfully identify individual players at greater risk of hamstring injury. This is evident in the large amount of variability between seasons, and poor sensitivity and specificity demonstrated for these measurements. The wide overlap in distribution of pre-season strength between injured and uninjured players demonstrates the difficulty in identifying a subgroup of at-risk players that might benefit from targeted intervention. It is therefore recommended that prevention programs be implemented for all players.
  4. Workload monitoring provide another potential way in which we may reduce the risk of injury. The aggregation of chronic workload, as well as careful planning of acute workload increases, may reduce the risk of hamstring injury. However, high-level evidence to support this is lacking.
  5. Understanding the context in which injuries occur and appreciating the complex nature of these injuries are important considerations to better manage players with hamstring injuries.



We continue to utilise performance tests when we assess risk of injury. Perhaps we need to consider what elements of the inciting event we could recreate in a safe way to test risk patterns and behaviour. This would include factors such as fatigue, dual cognitive tasks, and sport specific movements. Unfortunately, many sports medicine research groups continue to work in silos and ultimately answer similar research questions, published as isolated small studies. The clinical indications from these results often differ, and with the discrepancies among studies. A collaborative effort is needed to establish several well-organised successive research studies. This calls for a shared collaboration between institutions and research groups to perform collective data analyses and combine the results of individual projects.



Roald Bahr, M.D., Ph.D.


Oslo Sports Trauma Research Center Department of Sports Medicine, Norwegian School of Sport Sciences

Oslo, Norway


Nicol van Dyk, Ph.D.

Physiotherapist & Clinical Researcher

Aspetar – Orthopaedic and Sports Medicine Hospital

Doha, Qatar


Contact: nicol.vandyk@aspetar.com




  1. Bahr R, Clarsen B, Ekstrand J. Why we should focus on the burden of injuries and illnesses, not just their incidence. Br J Sports Med. October 2017:bjsports-2017-098160.
  2. Ekstrand J, Hagglund M, Walden M. Injury incidence and injury patterns in professional football: the UEFA injury study. Br J Sports Med. 2011;45(7):553-558.
  3. Ekstrand J, Gillquist J, Möller M, Oberg B, Liljedahl S-O. Incidence of soccer injuries and their relation to training and team success. Am J Sports Med. 1983;11(2):63–67.
  4. Hägglund M, Waldén M, Magnusson H, Kristenson K, Bengtsson H, Ekstrand J. Injuries affect team performance negatively in professional football: an 11-year follow-up of the UEFA Champions League injury study. Br J Sports Med. 2013;47(12):738-742.
  5. Eirale C, Farooq A, Smiley FA, Tol JL, Chalabi H. Epidemiology of football injuries in Asia: A prospective study in Qatar. J Sci Med Sport. 2013;16(2):113-117.
  6. Petersen J, Thorborg K, Nielsen MB, Budtz-Jorgensen E, Holmich 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(11):2296-2303.
  7. Van Der Horst N, Smits D-W, Petersen J, Goedhart EA, Backx FJG. The Preventive Effect of the Nordic Hamstring Exercise on Hamstring Injuries in Amateur Soccer Players: A Randomized Controlled Trial. Am J Sports Med. 2015;43(6):1316-1323.
  8. McCall A, Dupont G, Ekstrand J. Injury prevention strategies, coach compliance and player adherence of 33 of the UEFA Elite Club Injury Study teams: a survey of teams’ head medical officers. Br J Sports Med. 2016;50(12):725-730.
  9. Ekstrand J, Waldén M, Hägglund M. Hamstring injuries have increased by 4% annually in men’s professional football, since 2001: a 13-year longitudinal analysis of the UEFA Elite Club injury study. Br J Sports Med. 2016;50(12):731-737.
  10. Henderson G, Barnes CA, Portas MD. Factors associated with increased propensity for hamstring injury in English Premier League soccer players. J Sci Med Sport. 2010;13(4):397-402.
  11. Van Beijsterveldt AMC, van de Port IGL, Vereijken AJ, Backx FJG. Risk Factors for Hamstring Injuries in Male Soccer Players: A Systematic Review of Prospective Studies: Risk factors for hamstring injuries. Scand J Med Sci Sports. 2013;23(3):253-262.
  12. Freckleton G, Pizzari T. Risk factors for hamstring muscle strain injury in sport: a systematic review and meta-analysis. Br J Sports Med. 2013;47(6):351-358.
  13. Arnason A, Andersen TE, Holme I, Engebretsen L, Bahr R. Prevention of hamstring strains in elite soccer: an intervention study: Prevention of hamstring strains in soccer. Scand J Med Sci Sports. 2007;18(1):40-48.
  14. Emery CA, Meeuwisse WH. The effectiveness of a neuromuscular prevention strategy to reduce injuries in youth soccer: a cluster-randomised controlled trial. Br J Sports Med. 2010;44(8):555-562.
  15. Hartig DE, Henderson JM. Increasing hamstring flexibility decreases lower extremity overuse injuries in military basic trainees. Am J Sports Med. 1999;27(2):173–176.
  16. Bahr R, Thorborg K, Ekstrand J. Evidence-based hamstring injury prevention is not adopted by the majority of Champions League or Norwegian Premier League football teams: the Nordic Hamstring survey. Br J Sports Med. 2015;49(22):1466-1471.
  17. McCall A, Carling C, Davison M, et al. Injury risk factors, screening tests and preventative strategies: a systematic review of the evidence that underpins the perceptions and practices of 44 football (soccer) teams from various premier leagues. Br J Sports Med. 2015;49(9):583-589.
  18. van Dyk N, Bahr R, Whiteley R, et al. Hamstring and Quadriceps Isokinetic Strength Deficits Are Weak Risk Factors for Hamstring Strain Injuries: A 4-Year Cohort Study. Am J Sports Med. 2016;44(7):1789-1795.
  19. van Dyk N, Farooq A, Bahr R, Witvrouw E. Hamstring and Ankle Flexibility Deficits Are Weak Risk Factors for Hamstring Injury in Professional Soccer Players: A Prospective Cohort Study of 438 Players Including 78 Injuries. Am J Sports Med. 2018;46(9):2203-2210.
  20. Arnason A. Risk Factors for Injuries in Football. Am J Sports Med. 2004;32(90010):5S - 16.
  21. Opar DA, Williams MD, Timmins RG, Hickey J, Duhig SJ, Shield AJ. Eccentric Hamstring Strength and Hamstring Injury Risk in Australian Footballers: Med Sci Sports Exerc. 2015;47(4):857-865.
  22. van Dyk N, Bahr R, Burnett AF, et al. A comprehensive strength testing protocol offers no clinical value in predicting risk of hamstring injury: a prospective cohort study of 413 professional football players. Br J Sports Med. 2017;51(23):1695-1702.
  23. Bakken A, Targett S, Bere T, et al. Muscle Strength Is a Poor Screening Test for Predicting Lower Extremity Injuries in Professional Male Soccer Players: A 2-Year Prospective Cohort Study. Am J Sports Med. 2018;46(6):1481-1491.
  24. Opar DA, Williams MD, Shield AJ. Hamstring strain injuries. Sports Med. 2012;42(3):209–226.
  25. Mohr M, Krustrup P, Bangsbo J. Match performance of high-standard soccer players with special reference to development of fatigue. J Sports Sci. 2003;21(7):519-528.
  26. Bangsbo J, Mohr M, Krustrup P. Physical and metabolic demands of training and match-play in the elite football player. J Sports Sci. 2006;24(7):665-674.
  27. Hagglund M. Previous injury as a risk factor for injury in elite football: a prospective study over two consecutive seasons. Br J Sports Med. 2006;40(9):767-772.
  28. Hamilton GM, Meeuwisse WH, Emery CA, Steele RJ, Shrier I. Past Injury as a Risk Factor: An Illustrative Example Where Appearances Are Deceiving. Am J Epidemiol. 2011;173(8):941-948.
  29. Tol JL, Hamilton B, Eirale C, Muxart P, Jacobsen P, Whiteley R. At return to play following hamstring injury the majority of professional football players have residual isokinetic deficits. Br J Sports Med. 2014;48(18):1364-1369.
  30. Hamilton B, Tol JL, Almusa E, et al. Platelet-rich plasma does not enhance return to play in hamstring injuries: a randomised controlled trial. Br J Sports Med. 2015;49(14):943-950.
  31. Ekstrand J, Hagglund M, Walden M. Epidemiology of Muscle Injuries in Professional Football (Soccer). Am J Sports Med. 2011;39(6):1226-1232.
  32. Whiteley R, van Dyk N, Wangensteen A, Hansen C. Clinical implications from daily physiotherapy examination of 131 acute hamstring injuries and their association with running speed and rehabilitation progression. Br J Sports Med. October 2017:bjsports-2017-097616.
  33. Glasgow P, Phillips N, Bleakley C. Optimal loading: key variables and mechanisms. Br J Sports Med. 2015;49(5):278–279.
  34. Bahr R, Lian Ø, Bahr IA. A twofold reduction in the incidence of acute ankle sprains in volleyball after the introduction of an injury prevention program: a prospective cohort study. Scand J Med Sci Sports. 1997;7(3):172–177.
  35. Stark T, Walker B, Phillips JK, Fejer R, Beck R. Hand-held Dynamometry Correlation With the Gold Standard Isokinetic Dynamometry: A Systematic Review. PM&R. 2011;3(5):472-479.
  36. Andy Rolls, Alan McCall. No more poker face, it is time to finally lay our cards on the table. No More Poker Face It Time Final Lay Our Cards Table. March 2017.
  37. Mendiguchia J, Martinez-Ruiz E, Edouard P, et al. A Multifactorial, Criteria-based Progressive Algorithm for Hamstring Injury Treatment: Med Sci Sports Exerc. 2017;49(7):1482-1492.
  38. Croisier J-L, Ganteaume S, Binet J, Genty M, Ferret J-M. Strength Imbalances and Prevention of Hamstring Injury in Professional Soccer Players: A Prospective Study. Am J Sports Med. 2008;36(8):1469-1475.
  39. Cameron M, Adams R, Maher C. Motor control and strength as predictors of hamstring injury in elite players of Australian football. Phys Ther Sport. 2003;4(4):159-166.
  40. Sugiura Y, Saito T, Sakuraba K, Sakuma K, Suzuki E. Strength Deficits Identified With Concentric Action of the Hip Extensors and Eccentric Action of the Hamstrings Predispose to Hamstring Injury in Elite Sprinters. J Orthop Sports Phys Ther. 2008;38(8):457-464.
  41. Atkinson G, Batterham A. The Use of Ratios and Percentage Changes in Sports Medicine: Time for a Rethink?·. Int J Sports Med. 2012;33(07):505-506.
  42. Engebretsen AH, Myklebust G, Holme I, Engebretsen L, Bahr R. Intrinsic Risk Factors for Hamstring Injuries Among Male Soccer Players: A Prospective Cohort Study. Am J Sports Med. 2010;38(6):1147-1153.
  43. Opar DA, Piatkowski T, Williams MD, Shield AJ. A Novel Device Using the Nordic Hamstring Exercise to Assess Eccentric Knee Flexor Strength: A Reliability and Retrospective Injury Study. J Orthop Sports Phys Ther. 2013;43(9):636-640.
  44. Timmins RG, Bourne MN, Shield AJ, Williams MD, Lorenzen C, Opar DA. Short biceps femoris fascicles and eccentric knee flexor weakness increase the risk of hamstring injury in elite football (soccer): a prospective cohort study. Br J Sports Med. 2015:bjsports–2015.
  45. Bahr R. Why screening tests to predict injury do not work—and probably never will…: a critical review. Br J Sports Med. 2016;50(13):776-780.
  46. Witvrouw E, Danneels L, Asselman P, D’Have T, Cambier D. Muscle flexibility as a risk factor for developing muscle injuries in male professional soccer players a prospective study. Am J Sports Med. 2003;31(1):41–46.
  47. Fousekis K, Tsepis E, Poulmedis P, Athanasopoulos S, Vagenas G. Intrinsic risk factors of non-contact quadriceps and hamstring strains in soccer: a prospective study of 100 professional players. Br J Sports Med. 2011;45(9):709-714.
  48. Van Doormaal MCM, van der Horst N, Backx FJG, Smits D-W, Huisstede BMA. No Relationship Between Hamstring Flexibility and Hamstring Injuries in Male Amateur Soccer Players: A Prospective Study. Am J Sports Med. 2017;45(1):121-126.
  49. 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(1):7-13.
  50. Bennell K, Tully E, Harvey N. Does the toe-touch test predict hamstring injury in Australian Rules footballers? Aust J Physiother. 1999;45(2):103–109.
  51. Schuermans J, Van Tiggelen D, Witvrouw E. Prone Hip Extension Muscle Recruitment is Associated with Hamstring Injury Risk in Amateur Soccer. Int J Sports Med. 2017;38(09):696-706.
  52. Schuermans J, Van Tiggelen D, Palmans T, Danneels L, Witvrouw E. Deviating running kinematics and hamstring injury susceptibility in male soccer players: Cause or consequence? Gait Posture. 2017;57:270-277.
  53. 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(1):116-125.
  54. 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(3):696-703.
  55. Fyfe JJ, Opar DA, Williams MD, Shield AJ. The role of neuromuscular inhibition in hamstring strain injury recurrence. J Electromyogr Kinesiol. 2013;23(3):523-530.
  56. Zambaldi M, Beasley I, Rushton A. Return to play criteria after hamstring muscle injury in professional football: a Delphi consensus study. Br J Sports Med. 2017;51(16):1221-1226.
  57. van der Horst N, van de Hoef S, Reurink G, Huisstede B, Backx F. Return to Play After Hamstring Injuries: A Qualitative Systematic Review of Definitions and Criteria. Sports Med. 2016;46(6):899-912.
  58. Ekstrand J. A congested football calendar and the wellbeing of players: correlation between match exposure of European footballers before the World Cup 2002 and their injuries and performances during that World Cup. Br J Sports Med. 2004;38(4):493-497.
  59. Dennis R, Farhart R, Goumas C, Orchard J. Bowling workload and the risk of injury in elite cricket fast bowlers. J Sci Med Sport. 2003;6(3):359-367.
  60. Rogalski B, Dawson B, Heasman J, Gabbett TJ. Training and game loads and injury risk in elite Australian footballers. J Sci Med Sport. 2013;16(6):499-503.
  61. Gabbett TJ. Debunking the myths about training load, injury and performance: empirical evidence, hot topics and recommendations for practitioners. Br J Sports Med. October 2018:bjsports-2018-099784.
  62. Bakken A, Targett S, Bere T, et al. The functional movement test 9+ is a poor screening test for lower extremity injuries in professional male football players: a 2-year prospective cohort study. Br J Sports Med. May 2017:bjsports-2016-097307.
  63. Mosler AB, Weir A, Eirale C, et al. Epidemiology of time loss groin injuries in a men’s professional football league: a 2-year prospective study of 17 clubs and 606 players. Br J Sports Med. 2018;52(5):292-297.
  64. Rothman AJ. Causes. Am J Epi. 1976;104:587-593.
  65. Bolling C, van Mechelen W, Pasman HR, Verhagen E. Context Matters: Revisiting the First Step of the ‘Sequence of Prevention’ of Sports Injuries. Sports Med. 2018;48(10):2227-2234.
  66. Clarsen B, Myklebust G, Bahr, R. Development and validation of a new method for the registration of overuse injuries in sports injury epidemiology: the Oslo Sports Trauma Research Centre (OSTRC) Overuse Injury Questionnaire. Br J Sports Med. 2013;47:495–502.
  67. Windt J, Gabbett TJ. How do training and competition workloads relate to injury? The workload—injury aetiology model. Br J Sports Med. 2017;51(5):428-435.
  68. van Dyk N, van der Made AD, Timmins RG, Opar DA, Tol JL. There is strength in numbers for muscle injuries: it is time to establish an international collaborative registry. Br J Sports Med. May 2017:bjsports-2016-097318.


Figure 1: Distribution of injured (closed symbols) and uninjured players (open symbols) for significant variables a) strength and b) flexibility.
Figure 2: A socioecological view of sports injuries that includes context at multiple levels, i.e. individual, sociocultural and environmental. Bolling et al Sports Medicine (2018):1-8.


Volume 8 | Targeted Topic – Hamstring Injuries - Aspetar Experience | 2019
Volume 8 - Targeted Topic – Hamstring Injuries - Aspetar Experience

More from Aspetar Journal

Sports Science

Written by – Darren Paul, Qatar and Joao Brito, Portugal

Sports Rehab

Written by – Rod Whiteley, Qatar, Arnlaug Wangensteen, Norway, Nicol van Dyk and Philipp Jacobsen, Qatar

Sports Medicine

Written by – Cristiano Eirale and Jan Ekstrand, Qatar

Latest Issue

Download Volume 13 - Targeted Topic - Sports Medicine in Athletics | 2024


Sports Medicine
Sports Medicine


Member of
Organization members