What's wrong with my shoulder? my shoulder hurts when i lean forward & am using muscles to hold my arm in place instead of hanging forward, and also when i move my arm straight back. the pain is on the top & front, right in front of the end of my clavicl

It : It sounds like it may be a bursitis, which is an inflammation of the fluid-filled sac around the shoulder (there are bursa on other joints also). This can get inflammed for no reason. It sounds less likely to be rotator cuff issues since you can move your arm in most directions. It is important to be evaluated for this as bursitis can lead to a frozen shoulder (adhesive capsulitis). Please be sure you do gentle range of motion activities with your shoulder. Bend over and move your arm in little circles, or climb your fingers up the wall. You can take advil (ibuprofen) if you can tolerate it and don't have any reason that you can't take it (pregnancy, ulcer, etc). Please be evaluated by your doctor for your symptoms. If you have increased pain, any redness or swelling of the joint, fever, or pain in the chest, then please be seen immediately as an emergency.