Test-retest reliability of reciprocal isokinetic knee extension and flexion peak torque measurements

Our purpose in conducting this study was to estimate the reliability of reciprocal concentric knee extension and flexion peak torque obtained in uninjured male athletes using the Biodex isokinetic dynamometer. Twenty-six male intercollegiate athletes (age=19.5+/-4.1 yr; ht=70.3+/-14.9 in; wt=212.9+/-48.5 lb) participated in this study. We used the Biodex to measure peak torque occurring during right knee extension and flexion over 3 consecutive days. Means and standard deviations were calculated for both extension and flexion on each of the 3 days. We observed a significant main effect for days for both extension and flexion. Mean peak torque for the first day was significantly higher (Turkey, p<.05) than the means for the other 2 days, which were not significantly different from each other (Turkey, p>0.05). Intraclass correlation coefficients (ICCs) were estimated for each of the six trials on each of the 3 days. Intraclass correlation coefficients (ICCs) ranged from .88 on trial 1, day 1 for both extension and flexion peak torque to .97 for extension peak torque and .98 for flexion peak torque on day 3, trial 6. The standard error of measurement for extension peak torque was 7.0 ft-lbs and for flexion peak torque was 3.0 ft-lbs. These results indicate that reliable measurements of reciprocal right knee extension and flexion peak torque can be obtained from uninjured male athletes with the Biodex isokinetic dynamometer.