HAMSTRING STRAIN
Anatomy
The hamstring group of muscles, located on the back of the upper leg, are a group of three separate muscles: Biceps Femoris, Semimembranosus and Semitendinosus. The top of these muscles are attached to the lower part of the pelvis, and the bottom of the hamstring muscles are attached to the tibia and fibula (shin bones) just below the knee joint. The action of the hamstring muscles is to flex (bend) the knee and extend (straighten) the hip.
Signs and Symptoms
1 (Mild)
• Overstretching without tearing of muscle or tendon fibres.
• Symptoms may not present until activity is over.
• Usually no loss of muscular strength or flexibility.
• Increased tightness in the muscle during stretch or through a full range of motion.
• A feeling of pain may be reported with sitting or while walking uphill or ascending stairs.
• Depending on the severity, weight bearing activities may or may not be possible, walking properly may be possible and there will be minimal swelling.
2 (Moderate)
• Partial tear in the muscle.
• Muscular strength and flexibility is reduced.
• Pain is more immediate and more severe than the pain of a Grade 1 strain.
• Pain on stretch and contraction of the muscle, and is usually sore to touch.
• Limping is likely during walking and occasional sudden twinges of pain during activity may occur.
• Bending the knee against resistance will cause pain and there may be some difficulty in fully straightening the knee.
3 (Severe)
• Severe or complete rupture of the muscle. May be a large lump (of muscle tissue) above a depression where the tear is.
• Sudden, sharp pain in the back of the thigh.
• Walking is not possible without pain.
• After a few days with Grade 2 and 3 injuries, a large bruise may appear below the injury site caused by bleeding within the tissues.
• May require surgical repair.
Prevention
• Completing a thorough general body warm up, which includes sport-specific muscle stretching as well as sport specific skill drills.
• Including appropriate speed work in training programs so the hamstring muscles are capable of sustaining high acceleration forces.
• Maintaining high levels of cardiovascular fitness and muscular endurance to prevent fatigue.
• Stretching and cooling down after every training session and competition.
• Including stretching and strengthening exercises in weekly training programs.
• Undertaking training prior to competition to ensure readiness to play.
• Gradually increasing the intensity and duration of training.
• Allowing adequate recovery time between workouts or training sessions.
• Wearing the right protective equipment including footwear.
• Checking the sporting environment for hazards.
• Drinking water before, during and after play.
• Avoiding activities that cause pain. If pain does occur, discontinuing the activity immediately.
Rehabilitation and Return to Sport
Timeframes for rehabilitation and return to sport vary depending on the nature and severity of the strain. As a general rule, Grade 1 hamstring strains should be rested from sporting activity for about three weeks and Grade 2 injuries for a minimum of four to eight weeks. In the case of a complete rupture (Grade 3 strain), the muscle may have to be repaired surgically and the rehabilitation to follow will take about three months.
Premature return to sport and inadequate rehabilitation will increase the risk of re-injury. Full stretch and strength should be achieved in addition to the ability to perform full speed training. Assessment of sport-related activities, such as twisting, jumping and changing direction suddenly should also be evaluated.
For further information contact:
Sports Medicine Australia
www.sma.org.au www.smartplay.com.au References
For a full list of references, contact Sports Medicine Australia.
Acknowledgements
Sports Medicine Australia wishes to thank the sports medicine practitioners and SMA state branches who provided expert feedback in the development of this fact sheet
http://sma.org.au/wp-content/uploads/2011/01/719-SMA-InjuryBrochure-Hamstring_web.pdf