The piriformis is a fairly small muscle found deep within the hip joint, under the gluteus maximus muscle. The piriformis attaches the anterior surface of the sacrum (second to last section of the spine), and the head of the femur (large thigh bone); and it is surrounded by a handful of other small muscles. Together these muscles along with the piriformis are responsible for laterally rotating the hip, stabilising the hip joint and abducting the hip when it is in a flexed position. Running through the sacrum and under the piriformis is the sciatic nerve – the longest nerve in the body that spans from the lower spine to the foot – and provides both motor and sensory neurones to the leg. When piriformis becomes short and tight, it impacts on the sciatic nerve, which is the starting point for Piriformis Syndrome.
Tightness in the piriformis can be caused by a number of factors. It could be due to weakness or underuse of surrounding muscles, including the glutes, which leads to tightness in the piriformis; for example sitting for extended periods of time. Lower back problems, pelvic tilt or even injury can also cause the piriformis to become tight. Tightness in the muscle, in this scenario, means that the muscle has become shortened – the individual filaments that make up the muscle are contracted more than they should be at their resting length.
Due to the close proximity of the piriformis to the sciatic nerve, when the piriformis becomes short and tight, the sciatic nerve becomes compressed. When compressed pain occurs along the sciatic nerve, which can be particularly uncomfortable. It can lead to a dull ache or sharp pain in any location along the sciatic nerve, including the glutes, back of the thigh, calf and foot. Most commonly the pain will be at the source of the issue – where the piriformis muscle is compressing the nerve, however the pain can occur further along the nerve as well. Along with pain there can be weakness, stiffness, tingling and numbness at any point along the nerve too. This pain along the sciatic nerve is called sciatica. Sciatica can have numerous other causes, with piriformis syndrome being one of those causes. When the pain originates from the glutes, this can be a sign that the piriformis may be the cause.
By relieving the tightness in the piriformis muscle, the sciatic nerve can be relieved from it’s compression, which reduces the pain and discomfort experienced. However, it isn’t as simple as just relieving the tightness, since the underlying cause of the tightness needs to be identified and rectified in order to prevent reoccurrence. If someone is a desk worker for example, it may be difficult to completely prevent further issues, however having a standing/sitting convertible desk available can help, as well as short breaks to stand and stretch. On the other hand someone drives for a living, it might be difficult to make the necessary lifestyle adjustments, in which case they may need to implement a regular stretching routine into their day to day life.
Stretching the piriformis is a great way to prevent it from becoming too short, which can help to prevent a problem before it starts. Stretching can also help to lengthen the muscle (back to it’s normal resting length) if it has already become shortened. The image below shows some stretches you can do to keep your piriformis in good condition.