Tuberosity of the tibia of the large structure that acts as a lever to extend the knee-joint and prevents the knee from collapsing when the foot strikes the ground. The two ligaments, the patella, and the tibial tuberosity are all superficial, easily palpable structures. Tibial tuberosity fractures are infrequent fractures, most common in adolescents. In running and jumping movements, extreme contraction of the knee extensors can result in avulsion fractures of the tuberosity apophysis. A cast is all that is required if the fragment is not displaced from its normal position on the tibia. However, if the fracture fragment is displaced, then surgery is
Ball and socket joint the femur (ball) rests in the cup-like acetabulum (socket) of the pelvis, and in the glenohumeral joint of the shoulder, where the rounded head of the humerus (ball) rests in the cup-like glenoid fossa (socket) of the shoulder blade. The shoulder includes a sternoclavicular articulation 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