The Performance Demand Of Softball Pitching: A Comprehensive Muscle Fatigue Study
Jeffrey S. Corben, FACSM1, Sara A. Cerrone1, Julie E. Soviero1, Susan Y. Kwiecien2, Stephen J. Nicholas2, Malachy P. McHugh, FACSM2.
PURPOSE:Postgame muscle fatigue has been described for baseball pitchers (Mullaney et al 2005) but little is known about fatigue patterns in softball pitchers. The purpose of this study was to examine muscle fatigue after fast-pitch softball performances to provide an assessment of performance demand.
METHODS:Bilateral strength measurements (hand-held dynamometer) were made on 19 female softball pitchers (age 15.2±1.2 yr) prior to and after pitching a game (99±21 pitches, 5±1 innings). 21 tests were performed on the dominant (dom) and nondominant (ndom) sides: forearm (grip, wrist flexion/extension, pronation/supination, elbow flexion/extension), shoulder (flexion, abduction/adduction, external/internal rotation, empty can test), scapula (middle/lower trapezius, rhomboid) and hip (hip flexion/extension, abduction/adduction). Fatigue (% strength loss) was categorized based on bilateral vs. unilateral presentation using paired t-tests: Bilateral Symmetric (significant on dom and ndom, and not different between sides), Bilateral Asymmetric (significant on dom and ndom, but significantly greater on dom), Unilateral Asymmetric (significant on dom only, and significantly greater than ndom), or Unilateral Equivocal (significant on dom only but not different from ndom).
RESULTS:Bilateral Symmetric fatigue was evident for all hip tests (dom 19% ndom 15%) and scapula tests (dom 19% ndom 19%). In general, shoulder tests exhibited Bilateral Asymmetric fatigue (dom 17% ndom 12%). Forearm tests were more variable, with Bilateral Symmetric fatigue in the elbow flexors (dom 23% ndom 19%), and wrist flexors (dom 22% ndom 19%), Bilateral Asymmetric fatigue in the supinators (dom 22% ndom 16%), Unilateral Asymmetric fatigue in the elbow extensors (dom 22% ndom 11%) and Unilateral Equivocal fatigue in the pronators (dom 19% ndom 15%) and grip (dom 11% ndom 7%).
CONCLUSIONS:Previously baseball pitching was characterized by dominant shoulder fatigue, with minimal scapula or hip fatigue (Mullaney et al 2005). By contrast, softball pitching resulted in profound bilateral fatigue in the hip and scapular muscles with more selective fatigue in the shoulder and arm muscles. These findings emphasize the importance of strength in the proximal musculature to provide a stable platform for the arm to propel the ball.
1 Central Physical Therapy, Garden City, NY.
2 Nicholas Institute of Sports Medicine and Athletic Trauma, Lenox Hill Hospital, New York, NY.