Osseous adaptation and range of motion at the glenohumeral joint in professional baseball pitchers

Am J Sports Med. Jan-Feb 2002;30(1):20-6. doi: 10.1177/03635465020300011701.


The throwing shoulder in pitchers frequently exhibits a paradox of glenohumeral joint motion, in which excessive external rotation is present at the expense of decreased internal rotation. The object of this study was to determine the role of humeral head retroversion in relation to increased glenohumeral external rotation. Glenohumeral joint range of motion and laxity along with humeral head and glenoid version of the dominant versus nondominant shoulders were studied in 25 professional pitchers and 25 nonthrowing subjects. Each subject underwent a computed tomography scan to determine bilateral humeral head and glenoid version. The throwing group demonstrated a significant increase in the dominant shoulder versus the nondominant shoulder in humeral head retroversion, glenoid retroversion, external rotation at 90 degrees, and external rotation in the scapular plane. Internal rotation was decreased in the dominant shoulder. Total range of motion, anterior glenohumeral laxity, and posterior glenohumeral laxity were found to be equal bilaterally. The nonthrowing group demonstrated no significant difference in humeral head retroversion, glenoid retroversion, external rotation at 90 degrees or external rotation in the scapular plane between shoulders, and no difference in internal rotation at 90 degrees, total motion, or laxity. A comparison of the dominant shoulders of the two groups indicated that both external rotation at 90 degrees and humeral head retroversion were significantly greater in the throwing group.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological / physiology
  • Adult
  • Baseball / physiology*
  • Biomechanical Phenomena
  • Functional Laterality / physiology
  • Humans
  • Humerus / physiology
  • Joint Instability
  • Male
  • Range of Motion, Articular / physiology*
  • Reference Values
  • Shoulder Joint / physiology*