A number of factors and conditions can contribute to shoulder pain. The most prevalent cause is rotator cuff tendinitis.
This is a condition characterized by inflamed tendons. Another common cause of shoulder pain is an impingement syndrome where the rotator cuff gets caught between the acromium (part of the scapula that covers the ball) and humeral head (the ball portion of the humerus). Sometimes shoulder pain is the result of injury to another location in your body, usually the neck or bicep. This is known as referred pain. Referred pain generally doesn’t get worse when you move your shoulder.