The elbow joint is made up of three bones. The humerus is the bone in the upper arm and the ulna and radius are the two bones in the lower arm. The elbow is not as susceptible to injuries as weight bearing joints, like the knee and the hips, but it still has its fair share of injuries. The elbow can be affected by typical injuries, such as broken bones and stress fractures, as well as inflammation, such as tendonitis, arthritis and bursitis.
Your shoulder is a very mobile joint. Because it is so mobile, it is prone to specific types of injuries. These injuries can develop slowly over time, usually from repeated overhead movements or from a sudden injury.