Scapular force: Couple ratios in healthy shoulders - An observational study reflecting typical values.
Sonia Briel, Benita Olivier, Witness Mudzi
PMID 35937095WHAT IT FOUND
In healthy young adults, men are stronger than women in all shoulder muscles, but only some muscle balance ratios differ by sex.
No differences were found between dominant and non-dominant arms. These values apply only to pain-free shoulders aged 18-35 and do not indicate dysfunction.
Key findings
01Men had higher mean force values than women for all individual scapular muscles tested.
02There was no difference in muscle strength between the dominant and non-dominant sides in either men or women.
03Specific force couple ratios differed between sexes for the upper trapezius versus lower trapezius and middle trapezius versus serratus anterior upper fibres, but not for other couples.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The sample was restricted to healthy individuals aged 18-35, so these values cannot be applied to older adults or those with existing shoulder or neck conditions. The study measured resting muscle strength, not movement patterns, so it does not confirm whether these ratios predict or explain scapular dyskinesis during activity. The authors note that visual asymmetry in healthy people does not necessarily mean dysfunction, but the study did not directly measure scapular position or movement.
Declared interests
No specific funding sources or conflicts of interest were declared in the provided text.
The easy way to misread this
Do not interpret these force couple ratios as diagnostic criteria for shoulder pathology. The study was conducted entirely on pain-free shoulders, and the authors explicitly state that differences in these ratios do not indicate dyskinesis or dysfunction.