What causes shoulder pain? And how to get rid of them at home? And what is the cause of a crack in the shoulder? How do I know if the pain is caused by the shoulder or the heart? Most shoulder problems affect a small area, should last for a relatively short time, and are associated with shoulder pain. But sometimes, shoulder pain can be part of a larger, long-term problem, such as osteoarthritis or rheumatic muscle pain, according to Versus Arthritis.