The shoulder is the most mobile joint in the human body. The rotator cuff in the shoulder is made up of four tendons. These tendons give the shoulder a wide range of motion.
Any swelling, inflammation, tearing, or bony changes around these tendons causes pain when a person tries to move the arm above the head, behind the back, or straight out in front.
The tendons pass underneath a rigid bony arch in the shoulder. The most common cause of shoulder pain is when the tendons become trapped under this arch. The compressed tendons become inflamed or damaged, a condition called rotator cuff tendinitis. This can occur from:
• General wear and tear as you get older
• An activity that requires constant shoulder use, such as baseball pitching, or work activities in which you need to raise your shoulder
• An injury
Shoulder pain can also be due to:
• Arthritis in the joints around the shoulder (gradual narrowing of the joints and loss of protective cartilage).
• Bursitis (inflammation of a fluid-filled sac, or bursa, that lies between tendon and skin or between tendon and bone). Normally a bursa protects the joint and helps make movement more fluid.
• Fractures of the shoulder bones.
• Frozen shoulder syndrome occurs when the muscles, tendons, and ligaments stiffen up inside the shoulder and make any motion painful and difficult.
• Inflammation of nearby tendons, such as those connected to the bicep muscles of your arms, from overuse or injury.
• Dislocation of your shoulder, which is when the ball-shaped head of your arm comes out of the socket.