without these supernumerary muscular parts, actually occurs in only 20% of cases, and apparently the external obturator readily undergoes ontogenetic variations. Function The external obturator muscle acts as the lateral rotator of the hip joint. As a short muscle around the hip joint, it stabilizes the hip joint as a postural muscle. It also helps to abduct the hip joint when in flexion. Additional images See also References External links () PTCentral Hip muscles Deep lateral rotators of the hip Hip lateral rotators Medial compartment of thigh Muscles of the lower limb