The shoulder is a ball and socket joint in the upper extremity It is made up of the gleno-humeral joint, the acromio-clavicular joint and sternoclavicular joint. These joints are lined with cartilage (gristle) for smooth movement. Surrounding the joint is the capsule , and covering the capsule is the muscles and tendons.

Body Part


The shoulder is the most mobile joint in the body. Because of this it may sometimes move in ways that cause pain. This may be because of a slightly altered shoulder position, pathology in the tendons or an abnormal shape of the bone above: the acromion process of the shoulder blade. Impingement (or sub-acromial impingement) happens when the soft tissue over the shoulder (the rotator cuff and overlying fat) gets interfered with by the bone above (the acromion and clavicle).


This will lead to pain in certain positions of the arm, particularly when the arm is out to the side. This is known as a painful arc.


Once the diagnosis has been made, treatment involves recruiting the remaining intact fibres of the rotator cuff and the surrounding larger muscles to improve shoulder function with physiotherapy. This will be painful, particularly for the first month or so and you will require painkillers. If the symptoms improve and there is no functional impairment then there is no need for further intervention. If the symptoms do not improve, then you may require an injection for pain relief prior to continuing the physiotherapy. Your surgeon will normally only give you up to 2 injections. Further failure to control symptoms may necessitate discussion about surgery to repair the torn rotator cuff, which can be done using open or keyhole surgery.