The Piriformis muscle is an important muscle. The sciatic nerve passes underneath this muscle on its route down to the posterior thigh. In some individuals the nerve can actually pass right through the muscle. This can lead to sciatica symptoms due to a condition known as piriformis syndrome.
Origin : Anterior surface of the lateral sacrum
Insertion : Greater trochanter of the femur
Actions : External rotation of the hip.
Innervation : Branch of the sacral plexus
Daily uses : Taking the first leg out of the car
Example strengthening exercises : Hip extension with external rotation
Example stretches : Piriformis stretch
Related injuries : Piriformis syndrome
Related muscles : Gluteus minimus.