Hey, everyone! It’s Matt from Kenhub, and in this tutorial, we will discuss the origin, insertion, innervation, and function of the gluteus maximus.
The gluteus maximus muscle builds the most superficial layer of the dorsal gluteal musculature and so forms the surface anatomy of the gluteal region or buttocks.
The innervation is supplied by the inferior gluteal nerve, a branch of the sacral plexus. Numerous vessels and nerves run under the gluteus maximus muscle, including the sciatic nerve, the pudendal nerve, and the superior gluteal vessels.
The muscle originates from the sacrum (dorsal part), ilium (behind the posterior gluteal line), the thoracolumbar fascia, and the sacrotuberous ligament.
Its caudal fibers insert at the gluteal tuberosity of the femur. On the contrary, the cranial fibers go over into the iliotibial tract, a strong fibrous band at the outside of the thigh, inserting at the lateral condyle at the tibia.
The gluteus maximus muscle is the most powerful extensor and external rotator of the hip. It also supports the stabilization of the hip joint. The contraction of the cranial fibers leads to abduction, whereas the contraction of the caudal fibers causes an adduction.
The iliotibial tract enhances the lateral thigh fascia, and thus, relieves the pressure of the femur. That is also known as tension band principle.