Abstract
The purposes of the study were to (1) identify ratios for the evertor and invertor muscles of the ankle and (2) determine whether gender differences existed in ankle strength ratios of healthy, young adults. Twelve females and 13 males consented to be tested bilaterally on a single occasion for ankle inversion and eversion at two velocities (30 and 120 deg/sec) using the Cybex 330 isokinetic dynamometer (Cybex, Ronkonkoma, NY). Two- and three-way analyses of variance and post-hoc Neuman-Keuls tests were used to analyze the data. Results indicated that the invertor muscles were stronger than the evertor muscles at all velocities (26.31% at 30 deg/sec, 29.14% at 120 deg/sec), ankles tested (32.35% for the preferred, 22.23% for the nonpreferred), and genders (26.08% for males, 29.39% for females). With the exception of inversion at the slow velocity for the preferred ankle, there were no differences between the ankles for velocities or movements tested. Similar ratios of eversion/inversion strength were observed for each gender at either velocity. However, ratios differed significantly between the preferred (dominant) and nonpreferred (nondominant) ankles. It was concluded that individual ratios must be used to determine appropriate antagonistic strength ratios for the preferred and nonpreferred ankles (65% and 75%, respectively) and that no differences in gender effect were observed.