Impingement is a widely recognized cause of shoulder pain and potentially one of the most overdiagnosed conditions in the history of medicine.  The premise of impingement is a spur grows on the underside of one of the primary shoulder bones (acromion) and causes mechanical irritation and/or damage to the underlying rotator cuff tendons.  While this does happen, it happens far less frequently than previously thought. Often, what is called impingement, is an inherent inflammatory or degenerative condition of the rotator cuff tendon itself.  This is an important distinction to make as spur removal in this setting will not solve the problem, leading to an unsuccessful surgery and recovery. Rotator cuff tendonitis is typically most successfully treated with a nonsurgical approach.  Even when it is actually present, true impingement can often be treated with nonsurgical means. When these fail, surgical removal of the spur typically results in relatively rapid resolution of the problem.