The hip joint is a good example of a ball and socket joint. A ball and socket joint is so-called because of its general physical makeup, which consists of a bony pocket and a ball-like appendage on the connecting bone that fits within this pocket. This type of joint provides a wide range of motion in several directions as well as the ability to carry a great deal of strength. In addition to the hip joint, the shoulder joint is another example of a ball and socket joint.
The bones of this joint consist of the ilium, the femur and the ischium. The ilium contains “four spines serving as sites for muscle and ligamentous attachments” while “two large processes - an upper, lateral ‘greater trochanter’ and a lower, medial ‘lesser trochanter.’ … provide attachments for muscles of the legs and buttocks” (“Human Anatomy Online”, 2004). The important ligaments involved in this joint include the pubofemoral ligament, the iliofemoral ligament, the ligaments of the sacrum and the ischiofemoral ligament.
The major muscles involved in this joint include the iliopsoas muscles, the gluteous muscles, the piriformis and gemellus muscles, the sartorius muscle, the pectineus muscle, the quadriceps femoris muscles, the gracilis muscle, the adductor muscles and the hamstring muscles. The iliopsoas is actually two muscles that blend (“Human Anatomy Online”, 2004). The psoas major originates at the “sides of T12 to L5 vertebrae and intervertebral discs between them” and its insertion at the lesser trochanter of the femur. The iliacus originates at the iliac crest, iliac fossa, ala of sacrum, and the anterior sacroiliac ligaments while insertions are at the tendon of psoas major and the body of the femur, inferior to the lesser trochanter (“Muscles of the Hip and Thigh”, 1998). These muscles are the strongest flexor muscles of the thigh and work to maintain erect posture at the joints as well as to raise the trunk from a flat (lying