The isokinetic rotator cuff strength ratios in overhead athletes: Assessment and exercise effect.
Level 1 - systematic review of randomized trials
Systematic literature review with methodological quality assessment of included studies
PubMed 28648554 · doi:10.1016/j.ptsp.2017.03.001
What was done
A systematic review was conducted across PubMed and Web of Science to evaluate isokinetic internal rotator (IR) and external rotator (ER) muscle strength ratios (concentric/concentric and eccentric/concentric) in healthy overhead athletes. The review also examined the effect of exercise interventions on these strength ratios. Methodological quality of all included studies was formally assessed.
What was found
The abstract reports no numerical values. It found moderate evidence for a lower functional deceleration ratio (eccentric ER / concentric IR) in the dominant shoulder, driven primarily by disproportionately greater concentric IR strength on that side. There was no consensus on which exercise regimen is most effective for modifying shoulder isokinetic strength ratios.
Why it matters
Repetitive overhead throwing frequently creates muscular imbalances that may predispose athletes to shoulder injuries. Identifying a consistent deficit in the functional deceleration ratio highlights a specific target for screening and conditioning, although optimal training protocols remain undefined.
Limits
The abstract does not state the number of included studies or total participants, nor does it provide quantitative effect sizes. The literature search was limited to two databases. Furthermore, substantial heterogeneity or insufficient evidence prevented consensus on effective corrective exercise programs.
Cited by
- supports Eccentric contraction of the shoulder external rotators decelerates and controls the rapid internal rotation that occurs during throwing.