Relationship between scapular internal rotation and upper-trunk movements during right and left hand-behind-back movements.
Kanako Suzuki, Fumiko Kamijo, Naoya Nishinaka
PMID 39493680WHAT IT FOUND
Scapular movement during hand-behind-back tasks is linked to trunk motion, but the direction differs by side.
Right-hand movement correlated with trunk uprighting, while left-hand movement correlated with trunk forward flexion and rotation. Assess trunk posture separately for each side.
Key findings
01In the right hand, greater scapular internal rotation at the L3 position correlated with upper-trunk posterior tilt (uprighting), not anterior tilt.
02In the left hand, greater scapular internal rotation at both L3 and Th8 positions correlated with upper-trunk anterior tilt (forward flexion).
03In the left hand at the L3 position, greater scapular internal rotation also correlated with upper-trunk contralateral rotation.
STILL TO COME
How it was doneWhat they foundWhat it means for PTsWhat it means for OTsWhat it means for SLPs
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 consisted only of young, healthy, right-handed males, so results may not apply to women, older adults, left-handed individuals, or patients with shoulder pathology. The small sample size (n=20) limits the generalizability and statistical power, particularly for detecting non-significant trends. Skin marker movement can introduce error in the calculation of true joint angles. Participants had varying sports histories (excluding baseball), which may have influenced side-to-side differences.
Declared interests
The authors declared no conflicts of interest, and the research received no specific grant funding.
The easy way to misread this
Do not interpret the correlations as causation or a universal rule for all patients. The study was cross-sectional and small, and the direction of trunk tilt associated with scapular movement was opposite for the right and left hands. Applying a single trunk positioning strategy to both sides may be counterproductive.