Hip bone muscles. Monotremes and marsupials also possess a fourth pair of bones, the prepubes or "marsupial bones", which extend forward from the pubes, and help to support the abdominal muscles and, in marsupials, the pouch. In placental mammals, the pelvis as a whole is generally wider in females than in males, to allow for the birth of the young. The pelvic bones of cetaceans were formerly considered to be vestigial, but they are now known to play a role in sexual selection. Hip bone The hip bone (os coxa, innominate bone, pelvic bone or coxal bone) is a large flat bone,
Adductor muscles of the hip Adductor muscles of the hip The adductor muscles of the hip are a group of muscles mostly used for bringing the thighs together (called adduction). The adductor group is made up of: The adductors originate on the pubis and ischium bones and insert mainly on the medial posterior surface of the femur. The pectineus is the only adductor muscle that is innervated by the femoral nerve. The other adductor muscles are innervated by the obturator nerve with the exception of a small part of the adductor magnus which is innervated by the tibial nerve. In 33% of people a supernumerary