The shoulder is a ball-and-socket type joint (so is the hip joint). The ball at the top (head) of the upper arm bone (humerus) fits into the socket of the shoulder blade (scapula), and the ball-and-socket joint allows the arm to move in all directions. The rotator cuff consists of the muscles that attach the shoulder blade to the head of the humerus. The rotator cuff strengthens the shoulder joint and helps rotate the upper arm.
The glenoid labrum is a lip of strong connective tissue at the rim of the socket of the shoulder joint. The labrum helps keep the ball securely in the socket.
When people injure their shoulder, doctors can often diagnose the problem based on the physical examination. However, sometimes x-rays or magnetic resonance imaging (MRI) is needed.
Many shoulder injuries resolve with rest followed by rehabilitation exercises. Nonsteroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen) may also be used for short-term pain relief (for up to 72 hours). If pain persists for longer than 72 hours, the person should be referred to a specialist to determine if additional treatment (for example, corticosteroid injection or surgery) is needed.