What Is Semimembranosus Muscle Pain?
The semimembranosus muscle is one of the three hamstring muscles that make up the back of the thigh, along with the semitendinosus and biceps femoris. It is attached to the base of the pelvis, travels down the center of the back of the thigh, behind the knee, and connects to the top of the tibia, or shin, bone.
The muscle has several functions, including stabilization of the pelvis and extension of the hip joint, but its primary activity is flexion (bending) and internal rotation of the knee. As a result of its positioning, the muscle also plays an important role in limiting forward bending of the hip joint.
Causes of Semimembranosus Muscle Pain
Most commonly, semimembranosus muscle pain is the result of performing strenuous physical activity without sufficiently warming the muscles first. Activities that involve stretching out the muscles of the leg (such as hurdles or gymnastics) and sports that involve kicking (such as soccer or martial arts) are particularly common causes.
However, it is also possible to injure the hamstring through too little activity; sitting for long periods of time, especially on a hard surface that puts pressure on the muscle, can lead to the hamstring becoming strained and causing pain.
Symptoms of Semimembranosus Muscle Pain
Semimembranosus muscle pain can manifest in several different ways, which can make it difficult to identify the exact nature of the injury. The pain is typically felt just below the buttock or down the back of the thigh as low as the knee and may be exacerbated by walking, rising to stand after being seated, or strenuous activity. Other patients may experience deep pain in the thigh and knee while they are sleeping.
From the visible symptoms a patient is experiencing, it is possible to group hamstring injuries into three classes: Grade I (mild), Grade II (moderate), and Grade III (severe).
Mild injuries are typically characterized by stiffness and soreness in the muscle, with minimal impact on movement and little or no visible swelling. Moderate damage can be identified by noticeable swelling and bruising, and limitations to knee flexibility and ease of walking. Some patients may also find that the muscle becomes painful to touch. Severe hamstring injuries are those that continue to cause pain even when the patient is at rest, with noticeable swelling and bruising and an inability to walk without assistance.
The nature of the treatment given to a patient experiencing semimembranosus muscle pain is often determined by which grade their condition falls into.
Treatments for Semimembranosus Muscle Pain
Grade I and II injuries rarely require intervention from a physician. They will typically heal well without the need for treatment beyond resting the muscle from further overexertion and, if necessary, mild pain relief such as paracetamol or ibuprofen.
Grade III injuries, however, may need to be examined by a medical professional. As with more mild injuries, the best treatment is to rest the muscle, potentially for several weeks, to prevent any further damage from developing. Beyond that, a physician may prescribe anti-inflammatory medications to bring down any swelling, as well as providing the patient with a thigh wrap to support the muscle. They may also be able to advise the patient on a stretching and strengthening program to help rebuild muscle strength once the injury has healed.