Ball and socket joint Ball and socket joint The ball and socket joint (or spheroid joint) is a type of synovial joint in which the ball-shaped surface of one rounded bone fits into the cup-like depression of another bone. The distal bone is capable of motion around an indefinite number of axes, which have one common center. It enables the bone to move in many places (nearly all directions). An enarthrosis is a special kind of spheroidal joint in which the socket covers the sphere beyond its equator. Examples of this form of articulation are found in the hip, where the round head of
Hip pain Hip pain Pain in the hip is the experience of pain in the muscles or joints in the hip/ pelvic region, a condition commonly arising from any of a number of factors. Sometimes it is closely associated with lower back pain. Causes of pain around the hip joint may be intra-articular, extra-articular, or referred pain from neighboring structures, such as sacroiliac joint, spine, symphysis pubis, or the inguinal canal. Common etiologies include: Pain in the groin, called "anterior hip pain", is most often the result of osteoarthritis, osteonecrosis, occult fracture, acute synovitis, and septic arthritis; pain on the sides of