HOME HELP CONTACT US SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:
Sign In to gain access to subscriptions and/or personal tools.

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Request Permissions Request Reprints Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Maffet, M. W. Articles by Mathiyakom, W. Search for Related Content PubMed Articles by Maffet, M. W. Articles by Mathiyakom, W.

Shoulder Muscle Firing Patterns During the Windmill Softball Pitch

Centinela Hospital Medical Center, Inglewood, California

Frank W. Jobe, MD

Centinela Hospital Medical Center, Inglewood, California

Marilyn M. Pink, PhD, PT

Centinela Hospital Medical Center, Inglewood, California

John Brault, MS, PT

Centinela Hospital Medical Center, Inglewood, California

Witaya Mathiyakom, MS, PT

Centinela Hospital Medical Center, Inglewood, California

The purpose of this study was to describe the activity of eight shoulder muscles during the windmill fast-pitch softball throw. Ten collegiate female pitchers were an alyzed with intramuscular electromyography, high speed cinematography, and motion analysis. The su praspinatus muscle fired maximally during arm elevation from the 6 to 3 o'clock position phase, cen tralizing the humeral head within the glenoid. The pos terior deltoid and teres minor muscles acted maximally from the 3 to 12 o'clock position phase to continue arm elevation and externally rotate the humerus. The pec toralis major muscle accelerated the arm from the 12 o'clock position to ball release phase. The serratus anterior muscle characteristically acted to position the scapula for optimal glenohumeral congruency, and the subscapularis muscle functioned as an internal rotator and to protect the anterior capsule. Although the wind mill softball pitch is overtly different from the baseball pitch, several surprising similarities were revealed. The serratus anterior and pectoralis major muscles work in synchrony and seem to have similar functions in both pitches. Although the infraspinatus and teres minor muscles are both posterior cuff muscles, they are char acteristically uncoupled during the 6 to 3 o'clock posi tion phase, with the infraspinatus muscle acting more independently below 90°. Subscapularis muscle activ ity seems important in dynamic anterior glenohumeral stabilization and as an internal rotator in both the base ball and softball throws.

This article has been cited by other articles:

				M. J. DeFranco and M. S. Schickendantz Isolated Musculocutaneous Nerve Injury in a Professional Fast-Pitch Softball Player: A Case Report Am. J. Sports Med., September 1, 2008; 36(9): 1821 - 1823. [Full Text] [PDF]

				S. L. Werner, J. A. Guido, R. P. McNeice, J. L. Richardson, N. A. Delude, and G. W. Stewart Biomechanics of Youth Windmill Softball Pitching Am. J. Sports Med., April 1, 2005; 33(4): 552 - 560. [Abstract] [Full Text] [PDF]

				G. C. Dover, T. W. Kaminski, K. Meister, M. E. Powers, and M. Horodyski Assessment of Shoulder Proprioception in the Female Softball Athlete Am. J. Sports Med., May 1, 2003; 31(3): 431 - 437. [Abstract] [Full Text] [PDF]

				B. T. Kelly, S. I. Backus, R. F. Warren, and R. J. Williams Electromyographic Analysis and Phase Definition of the Overhead Football Throw Am. J. Sports Med., November 1, 2002; 30(6): 837 - 844. [Abstract] [Full Text] [PDF]

				K. Meister Injuries to the Shoulder in the Throwing Athlete: Part One: Biomechanics/Pathophysiology/Classification of Injury Am. J. Sports Med., March 1, 2000; 28(2): 265 - 275. [Abstract] [Full Text] [PDF]