Muscle Endurance Testing Using an Isokinetic Dynamometer and A Recumbent Stepper: A Correlation Study

Abstract

Purpose: A lack of objective and validated clinical measures to assess Quadriceps muscle endurance (ME) currently exists. The Transitt model of the NuStep recumbent stepper has the capability to measure ME but has not been validated. Therefore, the aim of this study was to investigate the association between ME measures on the NuStep and the isokinetic dynamometer (ID). Methods: 30 healthy individuals were recruited to participate. On both the NuStep (70°/90° knee flexion) and ID (70° knee flexion), the participants were instructed to hold a submaximal isometric unilateral knee extension contraction until exhaustion. Descriptive statistics, inferential statistics and correlation analyses were used with significance set at p<0.05. Results: There was excellent correlation (r between 0.813 to 0.840, p<0.001) between the average force generated by the individuals on the ID and the NuStep. There was a fair correlation (r between 0.331 to 0.413, p<0.05) for the ME measures between the ID and the NuStep. Conclusions: The NuStep shows excellent agreement for average force measurements. Future studies are needed to validate the NuStep as an objective measure of ME in both healthy and clinical populations.