What happens to the shoulder to cause it to become arthritic and painful?
The shoulder joint allows more range of motion than any other joint in the body. The cartilage that covers bone surfaces in the joint can begin to wear down, causing stiffness and pain. Some medical conditions — inflammation or rheumatoid arthritis — also can cause this type of degeneration. Direct injury to the shoulder joint from contact sports, an accident or a fall can destabilize the joint and cause uneven wear, eventually leading to arthritis.
