Internal obturator muscle

Internal obturator muscle

Latin	musculus obturator internus
Nerve	Nerve to obturator internus (L5, S1, S2)

The internal obturator muscle (Latin: musculus obturator internus ) is a muscle located in the pelvis and is part of the lateral rotator group of the hip joint. It plays a crucial role in the lateral rotation of the thigh and stabilization of the hip joint.

Origin and Insertion

The internal obturator muscle originates from the inner surface of the obturator membrane and the surrounding bone of the pelvis. It travels through the lesser sciatic foramen and inserts on the medial surface of the greater trochanter of the femur.

Innervation

The muscle is innervated by the nerve to obturator internus, which is derived from the sacral plexus with contributions from the L5, S1, and S2 nerve roots.

Blood Supply

The blood supply to the internal obturator muscle is primarily from the inferior gluteal artery.

Function

The primary function of the internal obturator muscle is to laterally rotate the thigh at the hip joint. It also assists in stabilizing the head of the femur within the acetabulum of the pelvis.

Clinical Significance

Injury or dysfunction of the internal obturator muscle can lead to pain or instability in the hip region. It may be involved in certain conditions such as piriformis syndrome or sciatica, where the muscle's proximity to the sciatic nerve can contribute to nerve compression.

See Also

• External obturator muscle
• Piriformis muscle
• Hip joint
• Lateral rotator group

References

• Gray's Anatomy
• Clinical Anatomy by Regions