 Weight training exercises where the arms are elevated above shoulder height but in an internally rotated position such as the upright row have been suggested as a cause of subacromial impingement.Another common cause of Impingement syndrome is restrictions in the range movement of the scapulo-thoracic surfaces.Commonly, a rib (or ribs) between rib 2 and rib 7/8 on the side of the impingement, may jut out slightly and/or feel hard when the person springs on it/them.