Piriformis syndrome is a condition in which the piriformis muscle irritates the sciatic nerve and causes pain in the rear and may cause pain along the back of the leg and into the foot (similar to sciatic pain). Piriformis syndrome is most common among women, and is thought to be common among active individuals (such as runners and walkers).
Piriformis syndrome can develop when the piriformis muscle becomes tight or spasms and places pressure on the sciatic nerve that runs beneath it. The pressure on the sciatic nerve can cause low back pain and/or pain that radiates to the rear and down the leg (similar to sciatica pain).
From a technical standpoint, piriformis syndrome does not cause true sciatica (as sciatica is usually defined as lumbar radiculopathy , or compression of a nerve root as it exits the spine). However, just like sciatica, piriformis syndrome can cause pain, numbness and tingling along the sciatic nerve, which runs down the back of the leg and into the foot.
Symptoms of piriformis syndrome:

Most commonly, patients describe acute tenderness in the rear and sciatica-like pain down the back of the leg. Typical symptoms of piriformis syndrome may include:

Symptoms of piriformis syndrome often become worse after prolonged sitting, walking or running, and may feel better after lying down on your back.
There are many treatments that can control your muscle spasms to control your pain, establishing and following your own treatment plan is key to pain management.