The break or fracture of the clavicle (collarbone) is a common sports injury associated with contact sports such as football and martial arts, as well as impact sports such as motor racing. A direct blow over the shoulder that may occur during a fall on an outstretched arm or a motor vehicle accident may cause the clavicle bone to break.
The humerus is the bone that forms the upper arm. It articulates with the glenoid cavity of the scapula (shoulder blade) to form the shoulder joint and with the lower arm bones – the ulna and radius – to form the elbow joint. The proximal humerus is the upper end of the arm bone that forms the shoulder joint.
The femur or thigh bone is the longest and strongest bone in the body, connecting the hip to the knee. A femur fracture is a break in the femur. The distal femur is the lower part of the thigh bone which flares out like an upside-down funnel and its lower end is covered by a smooth, slippery articular cartilage that protects and cushions the bone during movement.
The kneecap or patella forms a part of the knee joint. It is present at the front of the knee, protecting the knee and providing attachment to various muscle groups of the thigh and leg. The undersurface of the kneecap and the lower end of the femur are coated with articular cartilage, which helps in smooth movement of the knee joint.