What are they?
A partial or complete tearing of one or more of the three hamstring muscles that run from the back of the pelvis and attach on the shin bones. Strains of the hamstring are graded according to the degree of loss of function.
Grade 1 Strain: mild loss of muscle function with minimal loss of flexibility and strength.
Grade 2 Strain: significant loss of muscle function which causes significant loss of strength and flexibility.
Grade 3 Strain: all muscle fibres ruptured. Unable to walk without pain and gross loss of muscle strength and flexibility.
Causes of Hamstring Injuries
Hamstring injuries can occur due to overcontraction of hamstring either while it is working in a concentric muscle fashion (to flex the knee or extend the hip) or in an eccentric fashion (muscle working while it is lengthening as occurs when the hamstring muscle works to control the pace of knee extension prior to placing the foot on the ground during running). Hamstring injuries can also occur when bending forward quickly causing an excessive stretching of the hamstring that leads to muscle fibre tearing.
Biomechanical Factors that Contribute to Hamstring Injuries
- Hamstring muscle weakness;
- Gluteus maximus muscle weakness and inactivity;
- Hamstring muscle inflexibility;
- Pelvic asymetry;
- Hamstring/quadriceps muscle strength imbalance;
- Sciatic nerve irritation/tension; and
- Uncompleted rehabilitation from previous injury.
Treatment / Rehabilitation
- RICE (rest, ice, compression, elevation) for first 24-48 hours;
- Appropriate strengthening of the hamstring or gluteus maximus muscles;
- Hamstring stretches;
- Muscle energy techniques to correct pelvic asymetry;
- Lumbar spine mobilisation/manipulation to reduce sciatic nerve tension;
- Soft tissue massage and ultrasound therapy to loosen scar tissue;
- Graduated running program; and
- Eccentric flick/catch training.
Grade 1 hamstring strains usually recover in a 2-3 week period.
Grade 2 strains may take 3 –6 weeks.
Grade 3 strains can take anywhere from 8 weeks to 6 months to fully repair.
13th January 2013