Subacromial impingement syndrome. An outdated concept.

Subacromial impingement syndrome is still widely used amongst many health care providers including physiotherapists.

However, impingement of the rotator cuff is not an accurate explanation of the pathology. Back in 1983, Neers developed the concept of impingement syndrome. Yes, the guy who invented the Neer's test! It is thought that the impingement syndrome can be accentuated by close contact between the acromion and the rotator cuff while lifting the arm. 

With improved imaging techniques, this hypothesis is clearly inaccurate. 

More value is now placed on the role of degeneration in tendons which eventually develops into tears. 

 Thinking that every time a patient elevates the shoulder is impingement syndrome negatively affects outcome.

In fact, we impinge our shoulder on a daily basis, but most people don't have pain!

 Swimmers elevate their arms on a daily basis. Basketball players as well. But only some develop shoulder pain.

The evidence suggests that 80% of rotator cuff tears are actually located on the articular surface (UNDER) not the bursal surface! Acromiohumeral distance has very little to do with shoulder pain nor acromial angle. 

Pectoralis minor or scap. muscles have nothing to do with Subacromial pain.

Conclusion: Don't be afraid to raise your arm! You won't destroy your shoulder. Obviously, don't do anything excessively. Clinically, a patient may present with pain when he or she elevates the shoulder. This is more a consequence of the tendinopathy, NOT the cause. Work on gradual loading of the shoulder and eventually progress to overhead movements!

Stay AWAY from Kinesophobia!

PS: Let's call it Subacromial pain syndrome. It's not as specific, but when we don't know, we just don't know.

Reference: 

Diercks. Et al. Guideline for diagnosis and treatment of subacrioal pain syndrome. Acta Orthop (2014) 

Lawrence et al. the effect of glenohumeral plane of elevation on suprasipinatus subacromial proximity. (2018)