Hamstring strains are one of the most common injuries in all athletes. This injury is common in sports that require sprinting, jumping or acceleration or deceleration. The reason this relates to the type of muscle contraction that occurs with these sports. Concentric contractions occur when the muscle shortens to move the limb or body part. Eccentric contractions occur as the muscle is lengthening and these contractions are used to slow a movement that has already been initiated. Eccentric contractions place more force through the muscle than concentric. It is thought that this added force leads to muscle failure during an eccentric contraction.
ANATOMY OF THE HAMSTRING
The hamstring consists of three parts, semitendinosus, semimebranosus and biceps femoris which has a long and short head.
Muscle injury whether partial or complete occurs at the myotendinous junction where the force is greatest.
The healing process begins with inflammation,oedema and localised haemhorage. After an initial period of decreased tension, the healing muscle regains strength, as long as re-injury does not occur.
The protoclol of ice, rest and immobilisation is still the preferred approach to rehabilitation. After a period of immobilisation, mobilisation commences to properly align regenerating muscle fibres and limit the extent of connective tissue fibrosis. Pain free stretching and strengthening exercises begin to regain flexibility and prevent any further re injury. Proprioception and neuromuscular fascilitation must be restored to help prevent re -injury.
Return to competition commences when muscle imbalances are corrected and the hamstring-quadriceps strength ratio is 50% to 60% and the strength of the injured leg has been restored to within 10% of the uninjured leg.
If you would like further information on management or treatment for this condition contact:
Jan Naughton Sports Physiotherapy Wahroonga. Ph:02 94891246.
About the author:
Dr Jan Naughton received her PhD at Sydney University where she was lecturing in Sports Medicine and undergraduate physiotherapy. She specialises in shoulder injuries and has a sports physiotherapy practice in Wahroonga on Sydney's upper north shore working with two other specialist colleagues.