The piriformis muscle is found in the buttocks and extends for the front of the sacrum (the triangle bone at the base of the spine) and the top of the femur (leg bone). Its function is to help the leg move from side to side.
The piriformis (one in each buttock) stretches across the sciatic nerve, and so when this muscle becomes strained, tightened it can compress the sciatic nerve. This is piriformis syndrome.
As the sciatic nerve is compressed the main symptom of piriformis syndrome is sciatica. Although with piriformis syndrome the pain is felt mostly in the buttocks but in some cases referred pain may be felt in the leg.
With piriformis syndrome you may also feel:
- Numbness and tingling in the buttocks that may extend down the back of the leg
- Tenderness of the muscles in the buttocks
- Difficulty sitting comfortably
- Pain while sitting that gets worse the longer you sit
- Pain in the buttocks and legs that worsens with activity
The location of the piriformis in the body means that it gets extensively used every day. We sue it to walk, turn our lower body or shifting our weight from one leg to the other. The piriformis can become sore when we over or underuse it, or through strain or injury. For example:
- Over-use through excessive exercise
- Engaged in exercises that mostly involve the legs (eg running)
- Under-use through sitting for long periods of time and inactivity
- Lack of proper warm-up before exercise
- Strain from lifting heavy objects
- Sudden twisting or fall
- Car accident
In mild cases, the problem will often rectify itself with rest, especially if overuse is the cause.
Where the pain is more persistent the following can be used:
- Painkillers and/or anti-inflammatories.
- Alternating ice and heat packs on the buttocks and leg.
- Exercises aimed at stretching the muscle (where it has become tight) or building the muscle where it has become weak.
- Physical therapy can be used to relieve tightness.