The rotator cuff is a group of four muscle tendons that helps keep the shoulder in place, and rotator cuff impingement occurs when one of those muscle tendons becomes pinched against part of the shoulder blade, causing pain and limiting movement. This condition may be caused by repetitive movements involving the shoulder joint, especially where the arm is raised above the head. Rotator cuff impingement can be treated using a combination of rest, pain relief, steroid injections and physiotherapy. If it is left untreated, the tendon damage may worsen into a tear, possibly requiring surgical repair.
Four different muscle tendons make up the rotator cuff. These are the tendons of the subscapularis, teres minor, supraspinatus and infraspinatus muscles. The tendon most commonly involved in rotator cuff impingement is that of the supraspinatus muscle. Normally, when the arm is raised, the tendon of supraspinatus has to slide past part of the shoulder blade called the acromion process. If the shoulder joint is used excessively, repeated movement of the tendon can cause it to become damaged and inflamed.
A fluid-filled cushion called a bursa normally protects the rotator cuff from friction. This can also become inflamed, in a condition known as bursitis, and it may break down, in which case the cushioning effect is lost. The supraspinatus and other rotator cuff tendons are then exposed to increased rubbing and are more likely to deteriorate. Sometimes outgrowths of bone protrude from the shoulder blade, and these may also cause rotator cuff impingement by pinching one of the tendons.
Certain occupations predispose people to acquiring a rotator cuff impingement, typically those which involve a lot of physical activity, especially where the arms are raised, as in construction work or house painting. Some sports which involve heavy use of the upper limbs, such as swimming or tennis, can also increase the chances of a rotator cuff impingement occurring. Symptoms generally include pain in the shoulder joint which gets worse during movement and can also be present at night. If the arm is raised out to the side in an arc, pain will characteristically be felt as the arm moves through part of that arc.
Treatment to relieve the pain typically involves taking painkillers and anti-inflammatory drugs, applying ice and having steroid injections. Physiotherapy can be useful if the condition is mild, but surgery may be needed to resolve extreme cases. By widening the space inside the shoulder, tendinitis can be decreased, in what is known as a decompression procedure.