HAMSTRING STRAINS

Primary Injury and Structures Involved:     The hamstring muscles act as extensors at the hip and flexors at the knee joint.  Structures possibly involved in an injury are the biceps femoris, semimembranosus and semitendonosus muscles.  Exactly how the hamstrings are injured is unknown.  It is thought that a quick change of hamstring muscle from knee stabilization to extending the hip when running is a major cause of strain.

Grade 1 Strain -    No tearing of the muscle fibers.  The strain causes muscle soreness during movement, accompanied by point tenderness.  Irritation and stiffness occur after athlete has cooled down.

Grade 2 Strain -    Partial tearing of muscle fibers.  A sudden snap or tear of muscle occurs along with severe pain and loss of function during kee flexion.

Grade 3 Strain -    Rupture of muscle fibers, involving hemorrhage and disability.  Severe swelling, tenderness, loss of function, discoloration and palpable gap in muscle.

Specific Evaluation Techniques:     History, observation, palpation, and special tests are important to the evaluation.  Active and passive range of motion must be done along with resisted hip flexion, extension, adduction, abduction, and knee extension, flexion.

Treatment For The Injury:    
Acute:    Rest, Ice, Compression, and Elevation for 24 to 72 hours depending on the severity of the injury.  NSAID's (non-steroidal anti-imflammatory drugs; Aleve, Advil, etc.) and analgesics are given as needed.   Reduced activity until soreness has been eliminated.
Sub-Acute:    Isometric exercise, cryotherapy, massage and ultrasound may be helpful.  Gentle stretching within pain limits, jogging, stationary bike and isokinetic exercise at high speeds. 

IF AN ATHLETE DOES NOT SEEM TO BE HEALING, A PHYSICIAN REFERRAL MAY BE NECESSARY

The Sports Medicine Patient Advisor
by Pierre Rouzier, MD
Hamstring Strains pp 113-116