Validity of the IND IsoDyno isokinetic dynamometer maximum peak angular torque measure for right knee joint flexion and extension movement

Abstract

Context: IND IsoDyno isokinetic dynamometer is a newly designed dynamometer to measure the isokinetic strength of the knee joint. It is a cost-effective, clinically feasible, and easily available dynamometer which manifests its benefits over the preexisting one. Aim: The aim of this study was to assess the validity of IND IsoDyno isokinetic dynamometer with respect to maximum peak angular torque. Settings and Design: Criterion-related validity (concurrent validity). Materials and Methods: We considered IND IsoDyno isokinetic dynamometer as an index test and TecnoBody IsoMove isokinetic dynamometer as our reference standard. In this study, we assessed the validity of the IND IsoDyno isokinetic dynamometer and compared the obtained maximum peak angular torque values of the prototype device. Five volunteers were tested at 60° per second on concentric mode for knee flexion and extension on both the IsoMove and a new isokinetic dynamometer IND IsoDyno. Data for values of maximum peak angular torque were recorded. Statistical Analysis Used: Interclass correlation coefficient (ICC) and standard errors of measurement (SEM) were analyzed using IBM SPSS version 26. Bland and Altman's method of analysis was done. Results: ICC and SEM revealed a high level of reproducibility and precision in the device's maximum peak torque measurements. The 95% confidence interval (CI) interval falls between the limits of agreement on Bland and Altman's plot. Conclusions: Within the limitations of the study, IND IsoDyno isokinetic dynamometer provided a mechanically valid measure of maximum peak angular torque on multiple trials performed on various subjects.