To Impinge means to make an impression on something. In the case of shoulder impingement syndrome, this relates to a boney structure in the shoulder joint making an impression on the bursa and one of the muscles of the rotator cuff. If this persists, overtime the impression will wear on the underlying bursa and muscle tissue causing an irritation or even tear the muscle fibers. Sometimes as we age, shoulder impingement can be caused by a boney spur on the under side of the acromion process (see picture).
Signs and symptoms of a shoulder impingement include pain in the shoulder with overhead reaching, reaching behind the back, pain when reaching across the chest while rotating the arm downward. Sometimes this pain even feels like it is on the outside of the upper arm. Shoulder impingement pain will often awaken you while sleeping.
Treatment of the impinged shoulder can include conservative therapy consisting of anti-inflammatory medication, icing, rest and eliminating the movements that cause the pain. Additionally, physical or occupational therapy can be beneficial for pain relief, education and strengthening the surrounding musculature to provide relief from a possible muscular imbalance.
If conservative therapy is not successful, then surgical intervention may be warranted. This can either be done with an open incision or smaller incisions using an arthroscopic procedure. Both surgical procedures are aimed to increase the space where the tendon glides. If there are bone spurs on the under surface of the acromion, they are removed via an acromioplasty procedure. The end of the collar bone (clavicle) is often removed if arthritis is found about the acromion and clavicle joint (A-C joint).
Formal physical/occupational therapy is usually prescribed post shoulder impingement surgery. This will include patient education for nature of medical condition, precautions and contraindications. Pain management, range of motion and strengthening.