gluteus /glo̅o̅tē″əs/ , any of the three muscles that form the buttocks: the gluteus maximus, gluteus medius, and gluteus minimus. The gluteus maximus is a large muscle with an origin in the ilium, the sacrum, and the sacrotuberous ligament and an insertion in the gluteal tuberosity of the femur and the fascia lata. It acts to extend the thigh. The gluteus medius originates between the anterior and posterior gluteal lines of the ilium and inserts in the greater trochanter of the femur. It acts to abduct and medially rotate the thigh. The gluteus minimus originates between the inferior and anterior gluteal lines of the ilium and inserts in the greater trochanter of the femur. It acts to abduct the thigh.
