Piriformis

Piriformis

Latin	Musculus piriformis

The piriformis is a muscle in the gluteal region of the lower limb. It is one of the six muscles in the lateral rotator group. It is situated in the buttocks and serves both to rotate the hip and as a stabilizer of the hip joint.

Structure

The piriformis muscle originates from the anterior (front) part of the sacrum, the triangular bone at the base of the spine, directly above the tailbone. It exits the pelvis through the greater sciatic foramen to insert on the greater trochanter of the femur. Its primary function is to rotate the femur outward (lateral rotation) and to abduct the thigh when the hip is flexed.

Function

The piriformis muscle is important in the lateral rotation of the hip, a movement that is crucial in maintaining balance while standing and walking. Additionally, because of its unique position, the piriformis muscle helps to stabilize the hip joint by holding the head of the femur in the acetabulum, or hip socket.

Clinical significance

1. 1. 1. Piriformis Syndrome

Piriformis syndrome is a neuromuscular disorder that occurs when the piriformis muscle compresses the sciatic nerve, the largest nerve in the body. This compression can cause pain, tingling, and numbness in the buttocks and along the path of the sciatic nerve descending down the lower thigh and into the leg.

1. 1. 1. Diagnosis and Treatment

Diagnosis of piriformis syndrome is primarily based on the patient's history and physical examination, with imaging studies such as MRI used to rule out other possible causes of the symptoms. Treatment typically involves exercises to stretch and strengthen the piriformis and surrounding muscles, physical therapy, and medication for pain relief. In severe cases, injections or surgery may be necessary.

See also

• Musculoskeletal system
• Sciatic nerve
• Hip joint