BORSA, P. A., and E. L. SAUERS. The importance of gender on myokinetic deficits before and after microinjury. Med. Sci. Sports Exerc., Vol. 32, No. 5, pp. 891–896, 2000.
The purpose of this study was to determine the importance of gender on myokinetic deficits before and after muscle microinjury.
A repeated measures design assessed selected muscle force production characteristics in 20 male and 25 female volunteers. Peak force production (PFP) and the peak rate of force production (PRFP) were assessed before and over a 4-d period after an induced muscle microinjury.
ANOVA revealed statistically significant mean (±SD) differences between men and women for PFP and PRFP (P < 0.0001). Both genders demonstrated significant between-day differences for PFP (P < 0.016), whereas only men demonstrated significant between-day differences for PRFP (P < 0.016).
Our results reveal that muscle force generating capabilities of physically active men exceed that of women both before and after microinjury. Myokinetic deficits were most pronounced acutely, between 24 and 48 h postinjury, followed by a near complete recovery at day 4 (96 h postinjury). Both genders suffered acute and residual deficits for PFP, whereas only men showed significant acute deficits for PRFP. We recommend that athletes, both male and female, refrain from strenuous exercise at least 48 h postinjury, or until force-generating capabilities normalize. More research needs to be conducted to substantiate these findings.
Shoulder Kinematics Laboratory, Division of Kinesiology, University of Michigan, Ann Arbor, MI; and Biomechanics Laboratory, Department of Exercise and Sport Science, Oregon State University, Corvallis, OR
Submitted for publication February 1999.
Accepted for publication July 1999.
Address for correspondence: Paul A. Borsa, Ph.D., A.T.C., Director, Sports Medicine Research Laboratory, Oregon State University, 218 Langton Hall, Corvallis, OR 97331-3303; E-mail: Paul.Borsa@orst.edu.