Reliability of isokinetic ankle dorsiflexor strength measurements in healthy young men and women

The purposes of this study were: (i) to determine the test-retest reliabili ty of isokinetic ankle dorsiflexor strength measurements in young healthy a dults using the Biodex dynamometer, and (ii) to examine several statistical measures for the interpretation of reliability. Thirty men and women (mean age 23+/-3 years) performed three maximal concentric contractions at 30 de grees/s, 60 degrees/s, 90 degrees/s, 120 degrees/s and 150 degrees/s. Relia bility of peak torque, work and torque at a specific time were assessed by calculating the intraclass correlation coefficient (ICC (2,1)), Pearson pro duct moment correlation coefficient (r), standard error of the measurement (SEM), method error (ME) and coefficient of variation (CV), and by plotting the differences between observations against their means. Isokinetic tests of ankle dorsiflexor strength in healthy young adults using the Biodex dyn amometer were highly reliable (ICC 0.61-0.93). It is recommended that test- retest reliability analyses include the ICC and assessments of measurement errors (SEM, ME or CV), as well as graphs to indicate any systematic variat ions in the data.