Return to Play
A common threshold for return to play is when the strength of the injured hamstring has at least 90% of the strength of the unaffected hamstring and when the patient has full ROM. At least a 50-60% hamstring-to-quadriceps ratio is desired before allowing the athlete to return to play.
Strength testing is performed using isokinetic exercise equipment. In addition, it is also important to ensure the return of normal flexibility and endurance before the patient returns to play; reinjury is most often due to lack of both.
Therapy that incorporates sports-specific activities can help minimize the risk of reinjury.
Complications
Returning to play too early is a common factor leading to chronic hamstring pain and injury. Reinjury rates as high as 77% may be related to areas of calcification and inflammation in the hamstring after injury. Scar formation may impinge the sciatic nerve, resulting in hamstring syndrome. [18] Surgery has rarely been used to break up painful scar tissue.
Prevention
The implementation of proper warm-up and maintenance of flexibility and adequate strength are needed to prevent future injuries. The patient should be aware that as fatigue sets in, the risk of injury increases. With improved form and by emphasizing knee flexion during activities, the risk of further injuries is minimized. [2, 7, 8, 19, 20, 21]
Fifty Danish male professional and amateur soccer teams (942 players) were studied in a randomized controlled trial that compared a 10-week progressive eccentric training program followed by a weekly maintenance program. The overall results showed a significant reduction in hamstring injuries. The program was especially useful in prevention of recurrent injuries (number need to prevent 3), and to a lesser effect, the program was able to aid in the prevention of new injuries (number needed to treat 25). [22]
Prognosis
With minor activity limitations and proper rehabilitation, the prognosis is good for hamstring strains and even partial tears. Complete tears also heal but require a significantly longer and more intensive rehabilitation program.
