The impact of a functional ACL brace has on athletic performance is controversial. The purpose of this study was to determine effects of a functional ACL brace on key components of performance- strength and muscular endurance. Six female college soccer players, with no history of knee injuries, were tested with and without the brace. Each subject participated in three sessions, comprised of an orientation session and two randomly assigned experimental testing sessions conducted at least 24 hours apart. In the experimental sessions, subjects performed a 10-minute warm-up followed by muscular strength and muscular endurance tests on the Cybex Isokinetic Analyzer. Results with the brace provided overall trends that suggest a decrease in strength and muscular endurance of the flexor (hamstring) muscles. Results from the extensors (quadricep) muscles were mixed, with a decrease in muscular endurance, but an increase in strength. Overall, results suggest that wearing a functional ACL brace may negatively impact athletic performance.