This study found that subacromial distances were usually smallest below 70° of humerothoracic elevation.
In subjects with decreased scapulothoracic upward rotation, the minimum subacromial distance was about 35% smaller with the arm by the side and the range of subacromial rotator cuff contact was shifted to lower angles.
Despite this, subacromial contact during movement only occurred in 45% of participants, which may indicate that subacromial rotator cuff compression may be less common than traditionally presumed.
Decreased scapulothoracic upward rotation shifts the range of motion in which subacromial distances are smallest to lower angles.
This finding should assist in exercise prescription to avoid prolonged and repeated exposures within the range of closest proximity.
The lack of difference in the number of symptomatic patients in the low and high scapulothoracic upward rotation puts into question the relevance of this clinical finding.
> From: Lawrence et al., J Orthop Sports Phys Ther 49 (2019) 180-191 (Epub ahead of print). All rights reserved to Journal of Orthopaedic & Sports Physical Therapy. Click here for the online summary.
This is an interesting study, as it shows that not only: 1) there is a low prevalence of subacromial contact with the rotator cuff during abduction; but also 2) that the range of upward scapular rotation does not seem to influence this contact or its relation to pain complaints, instead just shifting it to lower ranges in decreased rotation.
If patients show complaints consistent with the regions of closer proximity according to their degree of scapular rotation, then it might be useful to adapt exercise prescription to more comfortable ranges.