SFaORZO, G. A., N.-M. CHEN, C. A. GOLD, and P. A. FRYE. The effect of prophylactic knee bracing on performance.Med. Sci. Sports Exerc., Vol. 21, No. 3, pp. 254–257, 1989. This study examined the effect of prophylactic knee bracing upon performance in 35 college-aged athletes. Twenty-five male and ten female subjects completed two sets of tests to determine quadriceps peak torque, rise time, time to fatigue, anaerobic power, and blood lactate accumulation. On one trial the subjects wore a Stromgren dual-hinged prophylactic knee brace. MANOVA analysis revealed that bracing did not significantly affect the performance of football players (males) but did inhibit the overall performance of lacrosse players (females) (P< 0.05).Post hocanalyses determined that rise time (time to develop peak torque) was the greatest contributor among the dependent variables to the multivariate difference observed in the females. However, no isolated variable was identified as significantly different between the conditions by repeated-measurest-tests. Additional analyses disclosed that familiarity with brace wearing, order of testing, or a trial effect (i.e., learning) did not alter the performance results. It was concluded that wearing a protective knee brace does not improve performance and may inhibit performance in some asymptomatic athletes. It is suggested that athletes and coaches reexamine the use of prophylactic braces based upon these findings and other research described in this paper.