The purpose of this study was to compare the effectiveness of ankle taping and a semirigid orthosis in providing ankle support before and after exercise. Twenty-two ankles were treated with ankle taping (treatment I) and a semirigid orthoses (treatment 11). Passive ankle inversion-eversion was measured on a Cybex IP prior to application of the treatment, following application of the treatment, and following a brief period of exercise. A two-way ANOVA and post hoc Tukey analyses indicated that post-application and post-exercise ankle motion was significantly less than preapplication motion for both treatment groups. However, inversion motion postexercise was significantly greater than pre-exercise motion for the taping condition, and the semirigid orthosis limited ankle motion significantly more than the taping treatment following exercise. The results suggest that a semirigid orthosis similar to the one tested in this study may be more effective in preventing ankle sprain njuries than athletic tape J Orthop Sports Phys Ther 1987;9(1):33-39.