Gluteus Minimus

What is the Gluteus Minimus

The gluteus minimus is the smallest and deepest of the three gluteal muscles. Like the gluteus medius, it has a fan-shaped appearance and lies on the outer surface of the ilium. It belongs to the group of medial rotators and abductors of the thigh and helps with keeping the pelvic region stable during movements.

Anatomy

Location and Attachments

Origin	The gluteal surface of the ilium, between the anterior and inferior gluteal lines
Insertion	Greater trochanter of the femur

Origin

The gluteus minimus originates from a broad area on the gluteal surface of the ilium, between the anterior and inferior gluteal lines. Additionally, some fibers may arise from the outer margin of the greater sciatic notch, near the point where the inferior gluteal line begins.

Insertion

The muscle fibers converge into a narrow, flat tendon, giving the muscle its characteristic fan-shaped appearance. This tendon courses laterally downward, crossing the hip joint capsule to insert onto the anterior surface of the greater trochanter of the femur.

Relations With Surrounding Muscles and Structures

It is the deepest of the superficial muscles in the gluteal (buttock) region, lying beneath the gluteus maximus, gluteus medius, and tensor fasciae latae. Although smaller in size, its shape and appearance resemble those of the gluteus medius, which completely covers its posterior surface. The deep branches of the superior gluteal artery and nerve course between these two muscles, running along the superficial surface of the gluteus minimus.

The piriformis muscle lies along the lower border of the gluteus minimus. In some anatomical variations, fibers of the gluteus minimus may blend with the piriformis or the superior gemellus, though this is uncommon.

Proximally, the muscle lies superficial to the ilium, while distally, it overlies the hip joint capsule and the reflected head of the rectus femoris.

A small bursa, sometimes called the trochanteric bursa of the gluteus minimus, is located between the tendon of the muscle and the greater trochanter. This bursa reduces friction as the muscle moves over the hip joint during activity.

Function

Action

Stabilizing the pelvis; abducting, and internally rotating the thigh

Like its appearance, the functions of the gluteus minimus also mirror those of the gluteus medius. 

Abducting the thigh

When the muscle contracts, it works in synergy with the gluteus medius and tensor fascia lata to move the thigh and the lower limb away from the midline of the body. The simplest example of this is the movement you make when you step sideways.

Rotating the thigh medially

As part of the medial rotator group, its anterior fibers contract to pull on the head of the femur and rotate the leg medially, or inwards, toward the other leg.

Stabilizing the pelvis and hip joint

With its attachments at the ilium and the hip joint, this muscle plays an important role in maintaining the stability of the pelvis and the hip joint during movements like walking and running. During walking, when one leg is off the ground (swing phase of gait cycle), the gluteus minimus on the stance side contracts to prevent the pelvis from tilting downwards on the unsupported (swing) side.

Antagonists

It works against the lateral rotators, including the piriformis, obturators, and quadratus femoris, during medial rotation of the thigh. Additionally

As a hip abductor, the gluteus medius is opposed by the hip adductors, adductor longus, brevis, magnus, gracilis, and pectineus, which draw the thigh toward the midline.

Innervation

Nerve

Superior gluteal nerve (L4-S1)

It is innervated by the superior gluteal nerve, originating from the posterior divisions of the L4, L5, and S1 nerves of the sacral plexus.

Blood Supply

Artery

Superior gluteal artery

The muscle’s main blood supply comes from the superior gluteal artery, a terminal branch of the posterior division of the internal iliac artery.

The muscle’s tendon also receives blood from the trochanteric anastomosis, which is formed by the superior and inferior gluteal arteries and the ascending branches of the lateral and medial circumflex femoral arteries.