Glenohumeral range of motion and stiffness in professional baseball pitchers.
OBJECTIVE
This study was conducted to perform kinematic measures in a group of asymptomatic professional baseball pitchers to determine side-to-side differences in passive glenohumeral range of motion (ROM) and stiffness. We hypothesized that the throwing shoulder in asymptomatic pitchers would display greater passive glenohumeral stiffness than the contralateral nonthrowing shoulder.


METHODS
Thirty-four professional baseball pitchers had bilateral assessments for passive glenohumeral ROM and stiffness during a single test session. ROM and stiffness measures were obtained objectively using standard goniometry and instrumented stress arthrometry, respectively.


RESULTS
The throwing shoulder had significantly less (-8.5 degrees) internal rotation and significantly more external rotation (5.1 degrees) than the nonthrowing shoulder (P < 0.01). Passive joint stiffness was not significantly different between the throwing and nonthrowing shoulder, and anterior joint stiffness was significantly greater than posterior joint stiffness for both shoulders (P < 0.05).


CONCLUSIONS
The repetitive stress of long-term throwing creates altered glenohumeral rotational patterns in the throwing shoulder of the professional baseball pitcher without compromising the joint's passive restraining quality.
Borsa
Paul A
PA
Sports Medicine Research Laboratory, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611-8205, USA. pborsa@hhp.ufl.edu
Dover
Geoffrey C
GC
Wilk
Kevin E
KE
Reinold
Michael M
MM
D000328:Adult; D001484:Baseball; D006801:Humans; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology*; D012785:Shoulder Joint / Q000502:physiology*; D014481:United States