Knee Injuries – Hamstring Strain

By Robert Donatelli, PhD, PT

The hamstrings are a group of three muscles located in the back of the thigh. They are referred to as two-joint muscles, and they connect the hip and knee. The hamstring muscles bend the knee and extend the hip as well as contribute to numerous other motions of the body’s lower extremity. Anyone who has injured their hamstrings has quickly discovered the important role they play and the importance of making them pain-free. 

Because of their multiple actions and their need for extension, the hamstring muscles are frequently vulnerable to strain. In fact, research indicates muscle strains occur most often in those like the hamstrings that cross two joints.


Hamstring Strain Symptoms

Muscle and hamstring strains are classified according to their severity:

1. A mild or first-degree strain is a tear of a few muscle fibers. Symptoms include minor swelling and discomfort with minimal or no loss of strength and function.
2. A moderate or second-degree strain involves greater damage of muscle with some loss of strength and function. Usually second-degree strains result in bleeding within the muscle secondary due to rupture of intramuscular blood vessels.
3. A severe or third-degree strain is a tear in the muscle extending across the whole muscle belly, resulting in total loss of muscle strength and function.

The good news is that most of the athletes I treat experience a first- or second-degree strain of the hamstrings. The not-so-good news, and research verifies this, is that athletes with a hamstring strain  usually experience significant, from four to six weeks, recovery time and are more susceptible to recurrent hamstring injury for about six months to one year. So how do we get, treat hamstring strains, and more importantly, how can we prevent them?


Treating Hamstring Strains

Treating a hamstring injury after the initial strain is the same as other soft tissue injuries. In the acute phase (2–4 days after the injury) you should control inflammation with ice, compression and elevation. This initial phase also involves early motion of the lower leg such as stationary bicycle and pool exercises involving kicking and walking in the water.

The subacute phase (5–10 days after the injury) treatment consists of early motion on a stationary bicycle, isolated hamstring resistive exercises and pain-free stretching. The remodeling phase (11–21 days out) involves continued resistive exercises isolating the hamstrings, stretching and lengthening muscle exercises called eccentrics. An example of this type of exercise is to lie on your stomach and slowly lower your leg from a flexed position. Also, be sure to take a look at the following SportsMD hamstring stretching videos.

The final phase, the functional phase, (22-90 days) includes continued strengthening and stretching as well as jogging, sprinting and sports-specific drills. This treatment regimen is usually successful in returning athletes to their specific sport within several weeks. However, to reduce the recurrence of the injury requires preventive strategies.


Preventing Hamstring Strains

Ever day in our clinic, we treat muscle imbalances. Muscles work in groups: some muscles move bones while others hold onto them. In this group work, where muscles are referred to as synergists, one muscle is the agonist and another is the antagonist. The dominant use of the hamstring muscle (the agonist) and the under-utilization of the hip extensor muscle or gluteus maximus (the antagonist) can be a major contributor to the hamstring’s susceptibility to injury. In a 2004 study published in the Journal Orthopedic and Sports Physical Therapy, titled “A Comparison of Two Rehabilitation Programs in the Treatment of Acute Hamstring Strain,” M. Sherry and T. Best revealed a more effective rehabilitation and conditioning program for hamstring strains. They found that a program consisting of progressive agility and trunk stabilization exercises was more effective than a program emphasizing isolated hamstring stretching and strengthening in returning athletes to their specific sport and preventing injury recurrence.

In our clinic we also have discovered that strengthening the hip and trunk are critical in treating hamstring strains. I refer to this approach as muscle balancing and it comprises three phases:

1. Identify, through a detailed evaluation, the weak muscles within the trunk, hips and pelvis.
2. Design a specific strengthening program for the weak muscles.
3. Perform sports-specific activities designed to challenge the muscles’ ability to work in a group without over-working or under-utilizing an individual muscle.

Keep your muscles balanced and you just may never experience the pain of a strain.


Disclaimer: SportsMD Media Inc. does NOT offer medical advice. The content on this website is for informational purposes only. Do not rely or act upon information from without seeking professional medical advice. Consultations on are not a substitute to physical consultation with a doctor or hospital services. The service should not to be used for medical emergencies. Do not delay seeing a doctor if you think you have a medical problem. In case of a medical emergency, call 911.

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