Comparison of the Isokinetic Torque Ratios and the Ratios of the Tensiomyographic Parameters of the Knee Muscles in Healthy Young Adults

Isokinetic dynamometry is considered the gold standard for assessing muscle strength ratios, whereas tensiomyography (TMG) has emerged as a promising tool for rapid assessment of involuntary muscle contractility. However, the validity of TMG-derived ratios for evaluating muscle balance around the knee remains unclear. The aim of this study was to examine the associations between various TMG-derived ratios of knee muscles and isokinetic torque ratios. Time- and amplitude-related TMG parameters, along with peak isokinetic torques at 60°/s, 180°/s, and 240°/s, were assessed in a sample of 30 healthy young adults of both genders. Conventional and functional torque ratios were linearly correlated with TMG ratios. Most correlations were not statistically significant and ranged from very weak to moderate (r = –0.251 to 0.124; p > 0.05). Only weak to moderate negative correlations between functional isokinetic knee muscle ratios and TMG ratios of contraction time and delay time were statistically significant (r = –0.366 to –0.468; p < 0.05), suggesting some meaningful relationships between the two assessment methods. Given the generally low strength of these associations, we conclude that TMG ratios should not be used as a direct substitute for isokinetic torque ratios. Due to the methodological limitations of this study, further research is needed to evaluate the functional validity of TMG-derived ratios.