Hamstring Tendonitis or Hamstring Syndrome
Hamstring injuries are common among active individuals, especially runners. Two conditions that cause similar symptoms are hamstring syndrome and hamstring tendinitis. Distinguishing between the two is important because the treatment is different.
The hamstring muscle group is made up of three different muscles, the biceps femoris, semitendinosus and semimembranosus. Two of these muscles (biceps femoris and semitendinosus) insert on the ischial tuberosities, the bottom part of the pelvic bones, commonly referred to as the sits bones. The hamstrings run all the way down the posterior thigh, crossing the knee joint and inserting onto the bones of the lower leg. They assist with bending the knee and extending the hip. Chronic microtears of the hamstring caused by inefficient running gait, muscular imbalances, or overuse can cause inflammation of the tendons where they attach leading to hamstring tendinitis. This injury is commonly seen in athletes and runners who have too long of a stride.
Hamstring syndrome has more neural involvement and can be caused by chronic or acute hamstring injuries. While the pain is similar to tendinitis, the cause is much different. In hamstring syndrome, the tendons attached to the sits bones become inflamed and form bands of tissue that can surround the sciatic nerve. This nerve begins at the spine and runs through the buttock and down the posterior thigh. It runs just outside of the sits bones and is very close to these hamstring attachments. Movements or activities that compress, stretch or irritate this nerve can cause severe pain. Most often, symptoms are felt when sitting because the sciatic nerve is being stretched (due to the flexed position of the hip), and compressed, (due to the close relationship to the sits bones). Pain when sitting is an important clinical symptom that helps to distinguish hamstring syndrome from hamstring tendonitis, but there are also some clinical tests that can help determine if the pain is caused by muscular or neural impairments.
Identification of the cause of hamstring pain is important because the treatment for these two injuries is different. Initially, both conditions will respond well to rest and decreased loads on the muscle. Hamstring tendinitis is treated by gentle stretching to relieve tension, cross friction massage to the tendons to stimulate healing, and strengthening of the lower extremities to address any weakness or muscular imbalances. Dry needling has also been shown to be effective to relieve any trigger points in the muscle bellies. Since tendinitis is a chronic issue, the patient’s mechanics when running, walking, or exercising also need to be addressed. Often, a shorter stride and increased cadence when walking and running can decrease the amount of tension and prevent further inflammation.
With hamstring syndrome, treatment initially focuses on reducing the tension and resting. Stretching of the muscles is not recommended because it will place increased tension on the sciatic nerve and will, often, cause increased pain and inflammation. Sitting on a wedge with the higher part positioned in the back, allows the hips to be flexed less and can provide some short term relief. Improving the mobility of the sciatic nerve can also be helpful. Since this nerve has such a close relationship to the gluteal and hamstring muscles, activities such as walking, squatting, and sitting require the nerve to move with the muscles. When it becomes stuck in one position, any movement that stretches or compresses the nerve can be very painful. Exercises can be given in an attempt to break up this tissue and gently glide the nerve up and down restoring mobility and relieving symptoms. Similarly to tendinitis, walking and running mechanics play an important role and both will be addressed in the later stages of treatment to prevent exacerbation and further injury to the tissues.
Pain with sitting is the number one sign that can differentiate hamstring tendonitis from hamstring syndrome but there are several clinical tests that can also be performed. These tests place the muscles and nerve in different positions to determine the source of a patient’s pain. In severe cases, both may be present. It has been shown that chronic hamstring injuries can lead to tendinitis AND hamstring syndrome, making individual assessment and treatment very important for full relief of symptoms.