Correlation of range of motion and glenohumeral translation in professional baseball pitchers.
BACKGROUND
Altered mobility patterns in the throwing shoulders of professional baseball pitchers have been reported. Most published reports examining glenohumeral laxity have not used an objective testing device.


OBJECTIVE
Quantify and compare glenohumeral translation and rotational range of motion between the throwing and non-throwing shoulders in professional baseball pitchers.


METHODS
Descriptive laboratory study.


METHODS
Force-displacement and range of motion measures were performed bilaterally on 43 asymptomatic professional baseball pitchers. Ultrasound imaging was used to measure glenohumeral translations under stressed and unstressed conditions.


RESULTS
No significant difference in translation was found between the throwing and nonthrowing shoulders. For both shoulders, posterior translation (5.38 +/- 2.7 mm) was significantly greater (P < .001) than was anterior translation (2.81 +/- 1.6 mm). External rotation in the throwing shoulder was significantly greater than that in the nonthrowing shoulder (P < .001), whereas internal rotation in the throwing shoulder was significantly less than that in the nonthrowing shoulder (P < .001). The total arc of rotation for the throwing shoulder was not significantly different than that for the nonthrowing shoulder, and correlation coefficients were poor between rotational and translational range of motion in the throwing shoulder, ranging from r = 0.232 to 0.209 between variables.


CONCLUSIONS
No significant difference in glenohumeral translation exists between the throwing and nonthrowing shoulders in asymptomatic professional baseball pitchers, posterior translation is significantly greater than anterior translation in the throwing shoulders of professional baseball pitchers, and glenohumeral translation is not related to rotational range of motion in the throwing shoulders of professional baseball pitchers.


CONCLUSIONS
Altered mobility patterns in asymptomatic professional baseball pitchers may be due to factors other than capsular adaptive changes.
Borsa
Paul A
PA
ATC, University of Florida, 149 Florida Gymnasium, PO Box 118205, Gainesville, FL 32611-8205, USA. pborsa@hhp.ufl.edu
Wilk
Kevin E
KE
Jacobson
Jon A
JA
Scibek
Jason S
JS
Dover
Geoffrey C
GC
Reinold
Michael M
MM
Andrews
James R
JR
D000328:Adult; D001484:Baseball / Q000502:physiology*; D001696:Biomechanical Phenomena; D006801:Humans; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology*; D012399:Rotation; D012785:Shoulder Joint / Q000502:physiology*