2. Pain from Moving the Arm Backwards
The rotator cuff is not a single muscle, but rather four muscles. These muscles are responsible for externally rotating the arm. This means these muscles are what allow you to turn the arm away from the body.
This could be in the form of swinging your fist outwards, or simply rotating the arm at the humerus into a supinated position. The rotator cuff is a very important muscle of the arm and shoulder. It is what helps you to be able to throw a ball and perform all sorts of movements of the arm.
If you notice that you are experiencing pain when you move your arm backward, the chances are very high that you have damaged your rotator cuff in some way. This is because the rotator cuff is the only muscle that helps with this type of rotation in the arm. Take note of the pain and speak to your doctor right away.