Pain in the shoulder particularly during overhead activity is a very common complaint in athletes or older age groups. It is important to first recognise shoulder impingement as a symptom and not as a diagnosis. There are two types of shoulder impingement, primary and secondary.
Older age groups generally suffer from primary impingement. This is due to excess bone growth in around the shoulder which encroaches on the space for the rotator cuff. Lack of space in this area causes irritation of the rotator cuff tendons which results in pain and discomfort, particularly in over head or external rotation movements.
Secondary impingement is generally caused by weakness of the muscles surrounding the shoulder. The serratus anterior muscle’s role, which is to help clamp the shoulder blade to the ribcage, is often weak in many people. Weakness of this muscle causes poor control of the shoulder blade in over head activities resulting in an impingement of the rotator cuff tendons. Tightness of the pectoralis minor which sits at the front of the shoulder and chest can exacerbate the problem by pulling and tilting the scapular forward.
Imbalance of the rotator cuff muscles in relation to the deltoid can also cause impingement. In particular the external rotator cuff muscles (infraspinatus and teres minor) become weak and fail to stabilise the head of the humerus (upper arm bone) as it slides and rolls under the acromion (part of the shoulder joint). This failure to stabilise the shoulder alters the biomechanics resulting in impingement and irritation of the superior shoulder muscles.
A rehabilitation protocol is an effective form of treatment for secondary impingement. Usually strengthening the shoulder stabilisers and the serratus anterior muscle, which we talked about earlier, is effective. Stretching of the pecs and front of the shoulder can also help return the shoulder to normal function.
Primary Impingement, depending on the seriousness of symptoms may require surgical intervention to alleviate pain and symptoms. It is recommended that you contact your therapist or doctor for advice if suffering from pain or discomfort.