Hamstring Strains & Treatment
Understanding your injury – Brisbane Physiotherapy Edition.
Overview of Hamstring Strains:
Description
- A strain to a large muscle group such as the hamstrings is the result of a substantial force during contraction or a violent stretch which causes mechanical stress. This results in varying degrees of rupture within the fibres of the muscle.
- They are usually a non-contact injury and mostly occur during sprinting where quick eccentric contractions are regular.
- Hamstring muscle injuries are a common injury in sports that involve high-speed running and kicking and affects mainly sprinters, hurdlers, long jumpers, footballers and field hockey players.
- Epidemiology
o They make up 15% of all injuries in AFL and 12% of all injuries in English football.
o They also have the highest recurrence rate of all injuries with a recurrence rate of 34% in AFL and 12% in English football.
Anatomy
The hamstring muscle group consists of three main muscles: biceps femoris, semimembranosus and semitendinosus. Most hamstring muscle injuries occur in the biceps femoris muscle.
Presentation
- Sudden onset
- Moderately severe pain with localized tenderness
- Disabling—difficulty walking, unable to run
- Decreased length of the hamstring muscle
- Reduced strength against resistance
- Local bruising
Grades of Muscle strain
Severity:
- Grade 0 - Muscle abnormality without evidence of pathology on imaging (Clinical syndrome)
- Grade 1 - Disruption of some muscle fibres / small tear
o Pain during or after activity
o May be pain on contraction, but no/minimal loss of strength
- Grade 2 Moderate tear to muscle
o Pain during activity which requires athlete to stop activity
o Pain on contraction and detectable weakness
- Grade 3 Extensive tear of muscle
o Sudden onset of pain and may fall to ground
o Significantly reduced ROM, pain on walking, obvious weakness
- Grade 4 Complete tear to muscle or tendon
o Sudden and onset of pain and significant / immediate limitation to activity
o Palpable gap, less pain on contraction than grade 3 injury
Anatomical site:
- ‘a’ Myofascial injury
o Peripheral aspect of muscle
- ‘b’ Injury within muscle belly
o Most common at muscle tendon junction
- ‘c’ Injury extends into tendon
o Or involves the central tendon of that muscle and generally these C type injuries have poorer prognosis, and that’s because the tendinous structures have a slower healing rate
Predisposing factors
- Intrinsic (personal-related)
o Age: increasing age is a risk factor for hamstring injury. This relationship may be due to decreased strength and an age-related reduction in muscle fiber size and number.
o Previous injury: past history of injury is associated with reduced strength.
o Flexibility: prospective studies have shown either a significant association between pre-season hamstring muscle tightness and subsequent development of a hamstring muscle injury or a tendency towards a statistical relationship.
o Strength: low hamstring strength has been shown to be a significant predictor of hamstring muscle strain injury.
- Extrinsic factors (environmental-related)
o Warm-up: muscle strain injuries, in general, are more likely to occur without adequate warm-up
o Fatigue: fatigued muscles are able to absorb less energy. Hamstring injuries are more common at the end of matches and training sessions.
o Fitness level: Inadequate pre-season training resulting in low fi tness levels may contribute to an increased hamstring injury rate.
o Training modalities: Too much emphasis on aerobic training instead of more high-intensity running/acceleration drills has been suggested as a causative factor. Abrupt increases in training volume and intensity may also contribute to injury risk.
Hamstring Strain Treatment
Treatment
- Acute Management (first 48hrs): RICE (Rest, Ice, Compression, Elevate) and pain free seated active knee extension.
- Soft tissue massage – hamstring and glute muscles.
- Strengthening:
o Eccentric + concentric hamstring exercises – eccentric strength is particularly important in recovery and prevention of recurrence of hamstring strains.
o Glute and adductor strengthening
- Progressive running program
- Manuel therapy to lower back if indicated.
- Neural tension exercises if indicated
Prognosis: Most hamstring strains take 4-6 week to recover. However, recovering from a hamstring injury may take days, weeks or months, depending on its severity.