INTERTRIAL RELIABILITY OF WORK MEASUREMENTS RECORDED DURING CONCENTRIC ISOKINETIC KNEE EXTENSION AND FLEXION IN SUBJECTS WITH AND WITHOUT MENISCAL TEARS

Intertrial reliability of work measurements was studied in 19 men with a partial medial meniscal tear (ME group) and in 10 men with no history of knee injury (control group). Three maximal voluntary concentric contractions of the muscles involved in knee extension (KE) and knee flexion (KF) were performed on a dynamometer at 30-degrees and 180-degrees/s using a preloading protocol. The subjects moved their legs through an arc of 90 degrees, and the work produced in the constant-velocity phase between 70 and 20 degrees of KE was computed for each trial. In ME group subjects able to perform three consecutive contractions (n = 12-14), high intertrial intraclass correlation coefficients (ICCs) were found (ICCs = .86-.92), except for KE work measurements at 180-degrees/s (ICC = .67). In the control group subjects, high ICCs were obtained for KE work measurements (ICCs = .87 and .95), whereas the low ICCs obtained for KF work measurements (ICCs = .64 and .79) increased to .86 and .93 when the first trial was removed. In both groups, a significant increase was found over the trials for KF measurements at 180-degrees/s and KE measurements at 30-degrees/s, but work measurements were shown to peak at the second trial. The results of this study suggest that the work produced on the second trial reflects a subject's maximal capacity. [Durand A, Malouin F, Richards CL, Bravo G. Intertrial reliability of work measurements recorded during concentric isokinetic knee extension and flexion in subjects with and without meniscal tears.