The piriformis muscle is located in the buttock region, deep to the gluteus maximus muscle and runs in a diagonal direction. As it is attached to both the anterior sacrum and the upper portion of the femur, it plays an important role in external rotation of the hip (turning the leg and foot outwards)
What causes piriformis syndrome?
The sciatic nerve is just beneath the piriformis muscle. The sciatic nerve can be compressed/irritated by the piriformis muscle which, in turn can cause pain, tingling, numbness and pins and needles along the back of the leg and in to the foot.
Although the exact cause of piriformis syndrome is unknown there are a few suspected causes:
-Sacroiliac joint irritation causing piriformis muscle spasms.
-Irritation of the piriformis muscle, causing it to spasm.
-Injury to the piriformis muscle cause tightening of the muscle.
-Injury to the piriformis muscle cause swelling of the muscle.
-Bleeding in the piriformis muscle area.
Signs, symptoms and diagnosis:
Despite there being no single diagnostic test for piriformis syndrome, the patient's symptoms and physical exam can lead to a diagnosis.
Common symptoms of piriformis syndrome include:
-Pain, pins and needle, numbness or weakness in the back of the thigh, calf or foot.
-A dull ache, pain, tingling or numbness in the gluteal region.
-Pain that is aggravated by walking up stairs or inclines.
-A reduced range at the hip joint.
-An increase in pain after prolonged sitting.
-Pain may be increased by a practitioner applying pressure to the piriformis muscle.
Ruling out other conditions that are a likely cause of the patient's symptoms, as well as a thorough assessment of their medical history, a physical examination and diagnostic testing is a common route in the diagnosis of piriformis syndrome.
References
Spine Health, 2012. What is Piriformis Syndrome? [Online] Available at: <https://www.spine-health.com/conditions/sciatica/what-piriformis-syndrome> [Accessed 14th September 2018].
SpineHealth, 2012. Symptoms and Diagnosis of Piriformis Syndrome. [Online] Available at: <https://www.spine-health.com/conditions/sciatica/symptoms-and-diagnosis-piriformis-syndrome> [Accessed 14th September 2018].
WebMD, 2018. Piriformis Syndrome. [Online] Available at: <https://www.webmd.com/pain-management/guide/piriformis-syndrome-causes-symptoms-treatments#1> [Accessed 14th September 2018].