Hamstring Strains

Background

There is a high likelihood that you or someone you know has sustained a hamstring strain at some point. It is one of the most common orthopedic traumatic injuries related to activity.  It’s been estimated that 12 to 15% of total injuries in sports classify as hamstring strains. This injury occurs when the muscle(s) on the back of your thigh are lengthened more than what is considered optimal. The mechanism of injury is often a result of running at high speeds, as well as changing directions quickly while running.  Risk factors can include such things as decreased hamstring strength, imbalance in quadriceps to hamstring ratio, stiffness, and decreased core stability. The most well documented risk factor by far though is a previous occurrence of a hamstring injury.

Diagnosis

The hamstrings are comprised of 4 different muscles (semitendinosis, semimembranosis, biceps Femoris short head, biceps Femoris long head).  The primary muscle typically involved in a hamstrings strain is the long head of the Biceps Femoris which is located on the outer or lateral aspect of the back of the thigh.  MRIs as a diagnostic tool have not been shown to add value over a clinical examination and patient history on predicting a time table for return to sport or activity. A recent study has shown that the length of the hamstring muscle that is tender on palpation has a high correlation on how long it will take to return to sport.  

Rehabilitation

Initially after a hamstring strain it is important to allow the scar tissue connecting muscle fibers to heal properly.  This area of the tissue is considered the weak link in the chain for the first 10 days following injury and it is important to allow the underlying physiological processes to occur.  A common error is to begin a stretching program during this time, but this can delay the healing process. With this being said, it also is not recommended to immobilize the leg after the injury.  Instead a program focused on isometrics is the best approach to start.   After this 10-day period of exercises focused on muscle contraction without joint movement it is safe to begin what are called eccentrics.  Nerve glides may also be integrated into the program during this time.  It is important to enter this phase safely but efficiently in order to prevent muscle atrophy and stiffness from occurring.  As you enter into the next phase you may gradually increase the load, reps, and speed of your exercises. The final step before return to sport is a monitored plyometric or explosive activity-based program.  This stage will simulate specific movements you perform in a sport or with general running activity.

Conclusion

The important thing to remember after a hamstring injury is the rehabilitation process is built upon phases.  A Physical Therapist can monitor you as you progress through these stages and provide appropriate exercises for each phase based on your own individual presentation.  It is easy to fall into the trap of moving too quickly through your rehabilitation and rush back to an activity too soon which can result in further setbacks. On the other side of the spectrum, passively waiting for things to go back to normal and not taking a proactive approach can provide a host of secondary dysfunctions in your lower extremities. Find the appropriate pace for YOU with the assistance of a PT by your side and get back in the game the right way.   Feel free to contact me or one of our other well qualified Physical Therapists for questions or to set up a consultation.

Information based on following Continuing education course for Physical Therapists:

“Rehabilitation & Prevention of Hamstring Strains”. Presented by Time Tyler MS, PT, ATC.  Medbridge. Medbridgeeducation.com.