Each gluteal muscle moves your thigh in different directions. Working together, your gluteal muscles affect your ability to stand from a squatted position, climb stairs and walk uphill. They also play an important role in maintaining your balance.
Anatomy and Function
The three gluteal muscles are the gluteus maximus, gluteus medius and gluteus minimus. The gluteus maximus muscle lies closest to the surface and attaches your pelvis to the upper thigh bone. This muscle moves your leg backward and out to the side and assists with outward rotation of your thigh. The gluteus medius lies underneath and slightly higher than the maximus, running from the top of your pelvis to the outer edge of your upper thigh bone. This muscle brings your leg out to the side and rotates it inward and outward. The gluteus minimus lies underneath the medius, attaching your pelvis to your upper thigh bone. This muscle mainly works with the medius to move your leg out to the side and to rotate your thigh inward.
The gluteus maximus muscle helps maintain your balance as you walk or run. As your leg comes forward and your heel hits the ground, this muscle tightens to slow down the forward movement of your leg and keep you balanced. When you run, this muscle tightens on the leg you are standing on to control the forward momentum of your trunk. Although the quadriceps muscles on the front of your thighs primarily move your legs forward as you walk or run, the gluteus maximus muscle tightens to help propel your body forward on hills or uneven surfaces. This muscle also lifts you from a squatted position and helps you climb stairs.
Pelvic stabilization is an important role of the gluteus medius. As you lift your leg to take a step, this muscle tightens on the stationary side to prevent your pelvis from dropping down when you pick your foot up. Weakness in this muscle causes an abnormal walking pattern called the Trendelenburg gait. When this occurs, the upper body leans over the leg you are standing on to shift your center of gravity over that leg to keep you balanced. Weakness in the gluteus medius will also shorten the length of your steps, making your walking less efficient.
As its name implies, the gluteus minimus is the smallest of your gluteal muscles. Depending on which part of the muscle is active, it can move your thigh forward, move it out to the side or rotate it inward or outward. Your hip is a ball-and-socket joint formed by your pelvis and thigh bone, and the gluteus minimus helps keep the ball in the socket as you move.