Anatomy, Bony Pelvis and Lower Limb, Piriformis Muscle

The piriformis is a flat, pear-shaped muscle located in the gluteal region of the hip/proximal thigh. It is one of the six short external rotator group muscles in the glulteal region of the proximal thigh. It courses parallel to the posterior margin of the gluteus medius, deep to gluteus maximus. The piriformis muscle has origins from several anatomical locations including the anterior surface of the lateral process of the sacrum, the spinal region of the gluteal muscles, and the superior/gluteal surface of the ilium near the margin of the greater sciatic notch, the capsule of the adjacent sacroiliac joint and sometimes from the sacrotuberous ligament. The muscle passes from the pelvis to the gluteal region by passing through the greater sciatic notch and inserts on the medial side of the superior aspect of the greater trochanter of the femur. The tendon of the piriformis muscle joins the tendons of the obturator internus and the inferior and superior gemellus (i.e. the conjoint tendon) before inserting on the femur. The muscle abuts the posterior wall of the pelvis and the posterior wall of the hip joint.Piriformis syndrome is a neurological disorder that often presents with hip and buttock pain.The syndrome is often misdiagnosed and undertreated.