Eccentric and concentric strength of the shoulder and arm musculature in collegiate baseball pitchers.
Level 4 - case-series / case-control
Cross-sectional observational study characterizing baseline muscle strength parameters in a single cohort without comparison to non-pitchers or longitudinal follow-up.
PubMed 8526283 · doi:10.1177/036354659502300520
What was done
Researchers measured bilateral isokinetic eccentric and concentric strength of the shoulder external/internal rotators and elbow flexors/extensors in 25 collegiate baseball pitchers. Strength testing was conducted across three velocities: 1.6, 3.7, and 5.2 rad/sec.
What was found
Internal rotators were consistently stronger than external rotators, with external-to-internal rotation strength ratios ranging from 62% to 81% across concentric and eccentric modes. Shoulder rotator eccentric strength averaged 114% of concentric strength. For the elbow, extension-to-flexion strength ratios ranged from 71% to 110%, and eccentric strength averaged 33% higher than concentric strength. No significant differences were observed between dominant and nondominant limbs for any strength measures or ratios.
Why it matters
Provides baseline normative reference values for both concentric and eccentric upper-extremity strength ratios in collegiate pitchers, which can inform conditioning and rehabilitation protocols.
Limits
The sample was small (N = 25) and limited strictly to healthy collegiate male pitchers. The study was descriptive and cross-sectional, so it did not track whether specific strength ratios or imbalances correlate with future injury risk or pitching performance.