Purpose
To compare kinematic and kinetic parameters between a cohort of fully recovered professional
pitchers with prior shoulder injury treated conservatively and a cohort with no prior
shoulder injury.
Methods
Twenty-six fully recovered professional baseball pitchers with a history of shoulder
injury treated conservatively pitched 8 to 10 fastball pitches using 3-dimensional
motion capture (480 Hz). All shoulder injuries occurred within a 1- to 4-year time
span from biomechanical evaluation and were severe enough to prevent pitchers from
playing for between 1 and 12 months. These pitchers were propensity score matched
by age, height, weight, handedness, and ball velocity to pitchers with no prior injury
history (control) at a ratio of 1:4. We compared 21 kinematic and 11 kinetic parameters
between groups using appropriate parametric testing. Subanalysis comparisons of pitchers
with prior SLAP injury as well as rotator cuff tendinitis were also performed.
Results
SLAP tears (n = 11, 42.3%) were the most frequently reported injury, followed by rotator
cuff tendinitis and/or shoulder impingement (n = 7, 26.9%). Compared with the control
group, the 26 pitchers with prior injury showed no significant differences across
the kinematic and kinetic factors. However, the SLAP tear subgroup did show significantly
less trunk rotation at foot contact compared with controls (34.1° ± 4.9° vs 39.2°
± 10.2°, P = .0075).
Conclusions
Fully recovered professional baseball pitchers with shoulder injuries treated conservatively
showed no significant differences in kinetics or kinematics compared with their propensity
score–matched counterparts, suggesting that shoulder injury alone may not greatly
alter pitching mechanics. However, whereas prior groups have shown a decrease in trunk
rotation at foot contact after surgical repair for SLAP tears, our study suggests
that this kinematic change may alternatively originate with the injury itself.
Clinical Relevance
Understanding the cause of biomechanical adaptations by pitchers after injury can
better aid clinicians and coaching staff in providing individualized and specific
care to the throwing athlete.
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Article info
Publication history
Published online: November 13, 2021
Accepted:
November 4,
2021
Received:
June 20,
2021
See commentary on page 1075Footnotes
The authors report the following potential conflicts of interest or sources of funding: J.S.D. is a consultant for Arthrex, Linvatec, Merck Sharp & Dohme, and Trice Medical and receives royalties from Linvatec, Wolters Kluwer Health–Lippincott Williams & Wilkins, and Zimmer Biomet, outside the submitted work Full ICMJE author disclosure forms are available for this article online, as supplementary material.
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