The gluteus medius is located on the lateral (i.e., external) side of your upper buttocks, and it’s responsible for the abduction of the leg (i.e., moving it away).
This muscle originates from the lateral surface of the ilium between the posterior and anterior gluteal lines, and similar to the deltoid muscle, the final insertion of the gluteus medius gets divided into three portions.
The mediation of walking, running, and single-leg weight-bearing activities
The support of the pelvis during gait
The complications that affect gluteus medius
The most common complication that affects this muscle is known as the Gluteus Medius syndrome, which describes a muscular injury that causes pain in the external side of the hip.
Physical therapists often refer to this condition as the rotator cuff of the hip due to the similarities in the pathogenesis and symptoms with the rotator cuff of the shoulders.
The most commonly affected structure in gluteus medius syndrome is the tendon that gets inflamed and could potentially lead to trochanteric bursa (i.e., the inflammation of a fluid-filled sac in the femur).