The obturator externus muscle covers the outer surface of the pelvis. The muscle is flat and fan-shaped. It lies deep in the medial compartment of the thigh and only visible when the pectineus muscle is reflected. The obturator externus muscle emerges from the margins of the obfurator membrane and obfurator foramen. The fibers of the obturator externus muscle converge and course behind the neck of the femur. It inserts into the trochanteric fossa of the femur. The obturator externus muscle helps to steady the head of the femur in the acetabulum of the pelvis. The obturator externus muscle also laterally rotates the thigh at the hip, with the help of the gluteus maximus and medius muscle. The gluteus maximus is the largest muscle in the human body. It is also the most powerful extensor of the hip. The gluteus medius is the chief abductor of the hip. It helps to steady the pelvis on the leg when the opposite leg is raised off the ground.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Obturator externus