Subacromial Impingement of the Shoulder
Of the multitude of problems that can cause pain in the shoulder, rotator cuff syndrome s generally the most common diagnosis.
What is rotator cuff syndrome and why is it so prevalent?
Rotator cuff is the term used to describe four muscles and their tendons that are aligned from front to back on the “ball” part of the shoulder joint which collectively suspends the shoulder, retain it in its socket and facilitate a variety of movement.
Without these muscles and tendons, shoulder function is significantly impaired resulting in weakness and pain especially in activities above shoulder height.
The biomechanical forces on these tendons can result in repetitive strain, inflammation and possible tearing and commonly, a fall onto the point of the shoulder can rupture or damage one of these tendons especially the ones located towards the front of the joint.
What are the characteristics of rotator cuff syndrome?
Typically, in the early stages, there may be local tenderness in the front of the joint with gradual onset of pain when lifting the arm away from the body and there may also be some pain and difficulty sleeping on the affected side.
A characteristic of rotator cuff syndrome is the presence of a painful arc. This occurs when the arm is lifted out to the side or even in front where pain emerges as the arm approaches the horizontal position (90°). If the arm can be lifted past this point of pain, full range motion can often be achieved without pain. Once again, sharp pain emerges as the arm is returned back to the side but only at the horizontal position.
Hence, this condition is also often referred to as “subacromial impingement”.