Impingement syndrome is a medical condition that affects a person's shoulder, states the Cleveland Clinic. It is most commonly seen in very active individuals and occurs whenever a person's rotator cuff is torn and the swelling from the injury begins to press on tissues and nerves in the shoulder.
Shoulder impingement can be a painful condition that may cause a variety of medical issues, states the Cleveland Clinic. Patients may exercise pain in their shoulder, behind their back, and in their arms if they develop this condition. If a patient has a complete rotator cuff tear, then he may also experience weakness in the affected shoulder and arm.