Risk Factors for Hamstring Injury

To follow on from the previous two blogs on assessment hamstring muscle flexibility and improving muscle flexibility, I thought it would a great time to discuss risk factors for injury too.

One of my old colleagues (and very talented young Physiotherapist) Grant Freckleton was involved in a 2013 study looking at the risk factors for hamstring injuries in Australian Rules Football players. I realise this is not a sport commonly played outside of Australia, but, the information is applicable and transferrable to other running/kicking sports with high prevalences of hamstring injury.

Prevalence & etiology

Hamstring muscle strain injuries (HMSI) are common in sports that involve sprinting (Orchard et al., 1997), acceleration, deceleration, rapid change in direction and jumping (Devlin, 2000; Drezner, 2003).

Hamstring injuries during sprinting are proposed to occur during the terminal swing phase of running as a consequence of an eccentric contraction (Schache et al., 2009; Heiderscheit et al., 2005).
The majority of hamstring injuries occur at the biceps femoris (BF) long head (Koulouris & Connell, 2005; De Smet & Best, 2000; Croisier, et al., 2004).
Askling, et al., (2006) has proposed two distinct mechanisms of hamstring injuries.

Type 1 involve high intensity running with injury occurring during late swing phase involving the proximal musculotendinous junction of the long head of biceps femoris.
Type 2 is described as a stretching of the hamstring complex due to extreme joint positions involving mostly semimembranosus and the proximal tendon (Yu et al, 2008; Askling et al, 2006).

Risk factors

A systematic review (Freckleton & Pizzari, 2013) identified:

Older age,
Increased quadriceps peak torque, and
Past history of hamstring injury as factors associated with increased risk of hamstring muscle strain injuries.
Interestingly hamstring:quadriceps ratio is not associated with hamstring injury.

Clinical assessment

The subjective assessment is key to correctly diagnose an injury. Players with a hamstring injury will report sudden onset of pain localised to the hamstring region with a clear mechanism or incident. Usually, players are unable to continue participating in their sport following injury. As mentioned above, previous history of injury is an important factor to question for during the subjective assessment as it is a major risk factors for future hamstring injuries (Freckleton, et al., 2012).

Clinical examination for determining hamstring injury is considered to be reliable and accurate (Schneider-Kolsky, et al., 2006). A hamstring injury can be defined as having positive clinical signs and symptoms including (Bennell, et al., 1999):

Immediate onset of posterior thigh pain,
Tenderness on palpation,
Reproduction of pain on stretch of hamstring,
Reduced straight leg raise ROM,
Reproduction of pain and reduced strength on resisted active contraction of hamstrings, and
Unable to continue playing or training and miss at least one game due to the hamstring injury.

Can we predict future hamstring injuries?

A recent study (Freckleton, et al., 2013) investigated the use of the single leg hamstring bridge (SLHB) as a clinical test in predicting hamstring injuries in football players.

The single leg hamstring bridge tests the hamstring muscles in a functional position similar to terminal swing and assesses endurance parameters rather than peak torque. This study demonstrated a significant deficit in preseason SLHB scores on the right leg of players that subsequently sustained a right-sided hamstring injury.

A score less than 20 is considered poor, 25 average and greater than 30 good. On average, players who sustained a right-sided hamstring injury in this study were close to or below the ‘poor’ level.

The SLHB test could be used to screen and identify athletes who are potentially at risk of sustaining a hamstring injury. It may also be used to evaluate the readiness of an athlete to return to sport.

The protocol is outlined in Freckleton et al. (2013). For the full details of this study please refer to the original blog post on Rayner & Smale.

Sian :)

Sian Smale is an Australian-trained and APA-titled Musculoskeletal Physiotherapist. Sian has been writing a Physiotherapy evidence-based blog for the past 3 years called Rayner & Smale. Sian is based out of San Francisco and continues to write and teach Clinical Pilates while working towards her Californian Physical Therapy license. Sian has also created a free, online pregnancy and post-natal home-based workout program Hey Fit Mama.

References:

Askling, C., Saartok, T., & Thorstensson, A. (2006). Type of acute hamstring strain affects flexibility, strength, and time to return to pre-injury level. British Journal of Sports Medicine, 40(1), 40-44.

Bennell K, Tully E, Harvey N. Does the toe-touch test predict hamstring injury in Australian Rules footballers? Aust J Physiother 1999;45:103–9.

Brukner, P., & Khan, K. (2006). Clinical sports medicine. McGraw Hill.

Croisier, J. L. (2004). Factors associated with recurrent hamstring injuries. Sports Medicine, 34(10), 681-695.

De Smet, A. A., & Best, T. M. (2000). MR imaging of the distribution and location of acute hamstring injuries in athletes. American Journal of Roentgenology, 174(2), 393-399.

Devlin L. Recurrent posterior thigh symptoms detrimental to performance in rugby union: predisposing factors. Sports Med 2000;29:273–87.

Drezner JA. Practical management: hamstring muscle injuries. Clin J Sport Med 2003;13:48–52.

Freckleton G, Pizzari T. Risk factors for hamstring muscle strain injury in sport: a systematic review and meta-analysis. Br J Sports Med 2013;47:351–8.

Freckleton, G., Cook, J., & Pizzari, T. (2013). The predictive validity of a single leg bridge test for hamstring injuries in Australian Rules Football Players. British journal of sports medicine.

Heiderscheit BC, Hoerth DM, Chumanov ES, et al. Identifying the time of occurrence of a hamstring strain injury during treadmill running: a case study. Clin Biomech 2005;20:1072–8.

Koulouris, G., & Connell, D. (2005). Hamstring Muscle Complex: An Imaging Review1.Radiographics, 25(3), 571-586.

Orchard J, Marsden J, Lord S, et al. Preseason hamstring muscle weakness associated with hamstring muscle injury in Australian footballers. Am J Sports Med 1997;25:81–5.

Orchard J, Seward H. The AFL Injury Report 2008. Australian Football League 2008.

Orchard J, Seward H. Orchard MJ. The AFL Injury Report 2012. Australian Football League 2013.

Pizzari, T., Wilde, V., & Coburn, P. (2010). Management of hamstring muscle strain injuries in the Australian Football League (AFL): A survey of current practice. Journal of Science and Medicine in Sport, 13, e76.

Pizzari, T., Taylor, R., & Coburn, P. (2012). The who, where and how.. Understanding hamstring injuries in the AFL. Journal of Science and Medicine in Sport, S143.

Schache AG, Wrigley TV, Baker R, et al. Biomechanical response to hamstring muscle strain injury. Gait Posture 2009;29:332–8. 12

Schneider-Kolsky M, Hoving J, Warren P, et al. A comparison between clinical assessment and magnetic resonance imaging of acute hamstring injuries. Am J Sports Med 2006;34:1008–15.

Upton PA, Noakes TD, Juritz JM. Thermal pants may reduce the risk of recurrent hamstring injuries in rugby players. Br J Sports Med 1996;30:57–60.

Yu, B., Queen, R. M., Abbey, A. N., Liu, Y., Moorman, C. T., & Garrett, W. E. (2008). Hamstring muscle kinematics and activation during overground sprinting. Journal of biomechanics, 41(15), 3121-3126.

Interested in live cases where I apply this approach and integrate it with pain science, manual therapy, repeated motions, IASTM, with emphasis on patient education? Check out Modern Manual Therapy!

Keeping it Eclectic...