22 Feb Hamstring Muscle Strain
When?
Hamstring strains are very common in sports involving sprinting, change of direction and jumping.
Most experts concur that the majority of hamstring strains occur while sprinting and more specifically as the lower limb is in the ‘terminal swing phase’ of running at a time when the hamstring muscle is loaded eccentrically(lengthening fibres under load).
Where?
The most common site of injury is in the biceps femurs (BF) – research indicating this is the case in approximately 80% of hamstring strains. Thirty percent of these BF strains are in the distal musculotendinous junction (MTJ) and twenty percent occur in the proximal MTJ and the remaining twenty percent are well localised to the mid belly.
Why?
The key risk factors are age, previous injury, fatigue and imbalance in quadriceps/hamstring strength ratio.
Diagnosis
Clinical examination is considered adequately reliable to make a correct diagnosis. The key positive clinical findings are:
(i) sudden onset with a mechanism of force/speed
(ii) disability walking or running
(iii) symptoms well localised on palpation
(iv) stretch deficit
(v) strength deficit
(vi) negative neural findings
Screening
A reliable clinical test to predict hamstring injury is the ‘single leg hamstring bridge’. If weak with endurance testing compared to the contralateral side there is an increased risk of forthcoming injury.
Treatment
Treatment is not limited to but can include:
(i) immediate RICER
(ii) early sub-threshold muscle stretching and activation
(iii) dry needling
(iv) soft tissue massage after early healing phase
(v) graduated return to activity over a 3-6 week period dependent on the grade of injury inclusive of well structured running drills that respect acceleration/deceleration
References:
Brukner + Kahn ,2006. Clinical Sp Medicine
Freckleton, Cook + Pizzari, 2013. BJSpMed
Freckleton + Pizzari, 2013. JSpMed
Orchard et al, 1997. AmJSpMed
Credit: Peter Hogg
APA Titled Sports Physiotherapist
