Gluteus minimus


The gluteus minimus, or glutæus minimus, the smallest of the three gluteal muscles, is situated immediately beneath the gluteus medius.

Origin and insertion

It is fan-shaped, arising from the outer surface of the ilium, between the anterior and inferior gluteal lines, and behind, from the margin of the greater sciatic notch.
The fibers converge to the deep surface of a radiated aponeurosis, and this ends in a tendon which is inserted into an impression on the anterior border of the greater trochanter, and gives an expansion to the capsule of the hip joint. It is also a local stabilizer for the hip.

Relations

A bursa is interposed between the tendon and the greater trochanter.
Between the gluteus medius and gluteus minimus are the deep branches of the superior gluteal vessels and the superior gluteal nerve.
The deep surface of the gluteus minimus is in relation with the reflected tendon of the rectus femoris and the capsule of the hip joint.

Function

The gluteus medius and gluteus minimus abduct the thigh, when the limb is extended, and are principally called into action in supporting the body on one limb, in conjunction with the tensor fasciæ latæ.
Their anterior fibers also flex the hip, and by drawing the greater trochanter forward, rotate the thigh inward, in which action they are also assisted by the Tensor fasciæ latæ.
Additionally, with the hip flexed, the gluteus medius and minimus internally rotate the thigh. With the hip extended, the gluteus medius and gluteus minimus externally rotate the thigh.
The attachment to the superior capsule of the hip may also serve to retract the capsule away from the joint during motion. This mechanism may prevent capsular impingement similar to the role of the articularis genus in the knee.

Variations

The muscle may be divided into an anterior and a posterior part, or it may send slips to the piriformis, the superior gemellus or the outer part of the origin of the vastus lateralis.

Pathology