gluteus

The gluteus, or gluteal muscles, refers to a group of three principal muscles in the buttocks: gluteus maximus, gluteus medius, and gluteus minimus. They cover the posterior aspect of the hip and proximal femur and are essential for moving the thigh at the hip joint and stabilizing the pelvis during walking and standing.

Gluteus maximus: the largest and most superficial gluteal muscle. It originates from the ilium posterior to the posterior gluteal line, the sacrum, coccyx, and sacrotuberous ligament, and inserts on the gluteal tuberosity of the femur and the iliotibial tract. Its primary actions are hip extension and external rotation, contributing to rising from seated positions, climbing, and sprinting. It is innervated by the inferior gluteal nerve.

Gluteus medius and minimus: located beneath and deep to maximus, respectively. They originate from the outer surface of the ilium and insert on the greater trochanter. Both muscles abduct the thigh and medially rotate the hip; the anterior fibers assist flexion and internal rotation and they stabilize the pelvis during gait. They are innervated by the superior gluteal nerve. The minimus lies deeper than the medius and shares similar actions.

Blood supply and clinical relevance: The gluteal muscles receive arterial blood from the superior and inferior gluteal arteries, branches of the internal iliac artery. Clinically, weakness or injury to these muscles can impair gait, producing a Trendelenburg sign or gait abnormalities, and gluteal tendinopathy or strains are common in athletes. Injections into the buttocks must avoid nerve damage, particularly to the superior gluteal nerve.