innervated by the posterior division of the obturator nerve while the hamstring portion is innervated by the sciatic nerve. Osseoaponeurotic openings At the insertion of the muscle, there is a series of osseoaponeurotic openings, formed by tendinous arches attached to the bone. The upper four openings are small, and give passage to the perforating branches of the profunda femoris artery. The lowest (often referred to as the adductor hiatus) is large, and transmits the femoral vessels to the popliteal fossa. Variation The upper, lateral part of the adductor magnus is an incompletely separated division often considered a separate muscle — the adductor minimus. These two muscles are frequently separated by a branch of the superior perforating branch of the profunda femoris artery. Function The adductor magnus is a powerful adductor of the thigh, made especially active when the legs are moved from a wide spread position to one in which the legs parallel each other. The part attached to the linea aspera acts as a lateral rotator. The part which reaches the medial epicondyle acts as a medial rotator when the leg is rotated outwards and flexed, and also acts to extend the hip joint. Other animals In other tetrapods, the adductor magnus crosses the knee joint and inserts into the tibia. In humans, the distal part of the tendon detaches and becomes the medial collateral ligament of the knee. Because of this, the medial collateral ligament of the knee in humans may contain a few muscle fibres as an atavistic variation. Additional images See also Adductor hiatus References External links PTCentral Hip adductors Thigh muscles Medial compartment of thigh