The gemellus inferior is one of the two small muscles known as the gemelli muscles located in the hip region. It is an accessory muscle to the tendon of the internal obturator muscle. The gemelli muscles belong to the lateral rotator group, which comprises six muscles that rotate the femur in the hip joint. The gemellus inferior originates from the upper part of the ischial tuberosity, just below the groove for the tendon of the internal obturator. It then blends with the lower part of the tendon and is inserted with it into the medial surface of the greater trochanter of the femur.

Functions: The gemellus inferior, along with the gemellus superior and the internal obturator muscle, contributes to steadying the femoral head in the acetabulum (hip socket). Additionally, these muscles aid in laterally rotating the extended thigh and abducting the flexed thigh at the hip, assisting the internal obturator in these actions. The gemelli muscles also play a compensatory role, providing additional power to the internal obturator as it turns around the lesser sciatic notch.