## 4 Discussion
In the same group, moderate negative correlations were also found between the maximum torque of the knee extensors at 60\({}^{\circ}\)/s (r = \(-0.514\); \(p<0.05\)) and 180\({}^{\circ}\)/s (r = \(-0.544\); \(p<0.05\)) and the Tc of the biceps femoris muscle [12]. In contrast, when comparing their results by gender alone, no statistically significant correlations were found between isokinetic measurements and any of the TMG time variables. In the next study with subjects of different muscle strength [13], the authors showed negative correlations between Tc of the biceps femoris muscle and knee extensor strength at 60\({}^{\circ}\)/s and 180\({}^{\circ}\)/s, as well as knee flexor strength at 60\({}^{\circ}\)/s and 180\({}^{\circ}\)/s in the low muscle strength group but not in the high muscle strength group. Thus, the trend of association between the flexor-to-extensor ratios calculated from the isokinetic peak torques and the TMG parameter Tc found in our study partially agrees with these results of [PERSON] et al. [12; 13]. It is important to emphasise, however, that the statistically significant correlations we observed were only low to moderate in magnitude, with isokinetic ratios accounting for merely 13-21% of the variability in TMG ratios. Therefore, the physiological and clinical relevance of these associations is likely to be limited. However, we found no significant relationship between the TMG ratios of the transverse displacement amplitude (Dm) of the knee muscles and their concentric and functional isokinetic torque ratios. This does not confirm the results of [PERSON] et al. [11], who reported significant positive correlations between knee flexor strength at 60\({}^{\circ}\)/s and the Dm of the vastus medialis muscle (r = 0.47). [PERSON] et al. [12] also found statistically significant but negative correlations between the Dm of the biceps femoris muscle and the maximum torque of the flexors and extensors at 60\({}^{\circ}\)/s and 180\({}^{\circ}\)/s in women, but only for the knee extensors at 180\({}^{\circ}\)/s in men. All correlations between Dm and the isokinetic torques of a given muscle were statistically significant but weak (r = \(-0.289\) to \(-0.390\)). In their later study [13], a significant negative correlation was also found between the Dm of the biceps femoris muscle and the strength of the knee extensors at 60 and 180\({}^{\circ}\)/s in the group of individuals with intermediate muscle strength. The fact that our initial hypotheses, which were based on previous associations between TMG and isokinetic dynamometric measurements [11; 12; 13], were not unequivocally confirmed by the experimental results may be attributed to several factors. Firstly, minor variations in electrode placement and skinfold thickness may influence the pattern of muscle fibre recruitment across individuals during electrical stimulation, potentially affecting Dm values. Nevertheless, the inter-rater reliability of the Dm parameter has been reported as good (r = 0.86) [25]. In our study, we further enhanced this reliability by ensuring that all TMG measurements were conducted by a single rater. Therefore, we believe that electrode placement did not constitute a source of error in our results. To further enhance the reliability of future measurements, it is recommended that skinfold thickness be precisely measured and documented. Secondly, although Dm and Tc are considered the most reliable TMG parameters [26] and therefore the best candidates for association with the isokinetic parameters, they may have the methodological disadvantage that they are linked, i.e., the higher the Dm, the longer the Tc. Therefore, the calculation of the contraction velocity (Vc), which is independent of the maximal amplitude of the muscle [19], might be better suited to detect correlations with the isokinetic parameters. Thirdly, the difference in the type of muscle contraction used for TMG and isokinetic dynamometry may also have influenced the magnitude of associations observed between the two.