For scapular upward rotation to occur, scapular downward rotator musculature must lengthen. If scapular downward rotation muscles are tight, they might not be flexible enough to allow for scapular upward rotation, thereby causing shoulder impingement syndrome to occur.
Shoulder impingement syndrome is a condition in which the distal tendon of the supraspinatus and the subacromial bursa become impinged between the head of the humerus and the acromion process of the scapula. Following are the six major causes of shoulder impingement syndrome.
The findings question the value of shoulder decompression surgery; this should be communicated to patients during the shared decision-making process.