The Study
Effect of Real-Time EMG Biofeedback on Selective Activation of the Infraspinatus and Posterior Deltoid During Theraband Shoulder External Rotation Exercise in Individuals with Round Shoulder Posture
This study is like comparing the same people doing two different things - once with a special screen showing their muscle activity, and once without. It found that when people could see their muscles working, they seemed to use their infraspinatus muscle more and their posterior deltoid less. But here's the tricky part: we can't be sure it was the screen that caused this change! The people might have just tried harder the second time, or other factors could have made the difference. It's like noticing you run faster when your friend cheers for you - you can't prove the cheering made you faster, just that they happened together.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Researchers tested whether seeing real-time muscle activity on a screen helps people better activate their infraspinatus muscle (the target muscle) while keeping the posterior deltoid muscle (an unwanted helper muscle) quiet during shoulder exercises.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 534 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The result shows that visual feedback helped people better control their shoulder muscles, which could improve rehabilitation outcomes for shoulder problems.
- 230 adults with rounded shoulders performed shoulder exercises with and without seeing their muscle activity on a screen.
- 3When they could see the feedback, they activated their infraspinatus more and their posterior deltoid less.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of Mechanics in Medicine and Biology
Year
2026
Authors
Donghyun Yi, One-bin Lim, Min-Hyeok Kang, Hyeok Kim
Related Content
Claims (5)
Using a machine that shows muscle activity in real-time while doing shoulder exercises helps people with rounded shoulders activate their back shoulder muscle more than the back part of their shoulder muscle, which is a good thing for shoulder health.
When adults with rounded shoulders use a device that shows them their muscle activity in real-time while doing a shoulder rotation exercise, it helps them reduce overactive muscles in the back of the shoulder that cause problems.
When someone has rounded shoulders, the back part of their shoulder muscle might work too hard when rotating the shoulder outward. This could throw off the normal muscle balance around the shoulder joint and lead to shoulder problems.
When people with rounded shoulders do a shoulder rotation exercise while getting real-time feedback from muscle activity sensors, their infraspinatus muscle works harder compared to doing the exercise without feedback.
Using a screen that shows muscle activity in real-time while doing a shoulder rotation exercise might help people with rounded shoulders move better and recover faster from injuries.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.