## 4 Discussion
Analysing the results presented in a chart of Figure 3A and the data in Table 4 referring to the normative values of rsEMG amplitudes recorded in the healthy volunteers for all key muscles under this study, it can be concluded that the amplitude less than 25 \(\upmu\)V can be considered as normal, indicating the proper muscle tension. The muscle tension of iSCI patients in our study scored more than 1 in MAS (meaning a slight increase in muscle tone) was not always related to the neurophysiological limit describing the increased muscle tension. None of the iSCI patients in this study received a 0 score in MAS; however, some of them had less than 25 \(\upmu\)V-amplitudes in rsEMG recordings, which means normal muscle tensions in terms of neurophysiology. It is important to remember that MAS scale evaluation is affected by the error of subjective assessment. For this reason, objective rsEMG measurements may offer a valuable advantage over MAS in the assessment of patients exhibiting presumed spasticity symptoms due to their superior precision. Another crucial aspect is that these numerical scales may not be precise enough to detect subtle changes in muscle function after iSCI; it is impossible with the help of Lovett and MAS to analyse subclinical stages. However, in studies by [PERSON] et al. [41], the inter- and intra-rater agreement for Modified Ashworth Scale scores were satisfactory. In their studies, MAS scores exhibited better reliability when measuring upper extremities than lower. Several characteristics of the studies were statistically associated with an inter-rater reliability of the scores for the lower and upper extremities. On the other hand, there are inconsistent opinions on the utility of MAS and the Lovett Scale in the clinical evaluation of patients with different movement disorders [42; 43]. [PERSON] et al. stated that MAS has adequate reliability for determining lower-extremity spasticity in patients with iSCI [43]. On the other hand, [PERSON] et al. [44], utilising sEMG for evaluation of the spasticity syndrome, suppose that the validity and reliability of MAS are insufficient to be used as a measure of spasticity. Patients who are evaluated on the Lovett Scale, or MAS, by physiotherapists very often, despite intensive rehabilitation, receive the same score, which does not illustrate real patient progress. Thanks to clinical neurophysiology studies, we are able to evaluate changes in the amplitude and nature of the recording that are subclinical. This may have a significant impact on patients' motivation for further rehabilitation. In addition, it is a tool that gives those in charge of rehabilitation detailed information, thus, a detailed understanding of the nature of the changes and which direction the rehabilitation program should go. In addition, the results obtained in the sEMG test are easier to compare with each other among other researchers, and even the smallest differences, not to be captured in the MAS and Lovett Scales, can be measured. Such an approach highlights the importance of a comprehensive evaluation that may become a key motivation for a patient's further rehabilitation process. There is little consistent data on the utilisation of sEMG for the evaluation of motor unit activity from different muscle groups of iSCI patients [36; 37; 45]. The exceptions are the research of [PERSON] et al. [32; 33], who utilised sEMG to program the algorithm of the diagnostic evaluation of the iSCI patients with different levels of injury, with the rules of recordings interpretations very similar to the ones proposed in this study. Only the study of [PERSON] et al. [38] is comparable with our final results in the evaluation of mcsEMG frequency index (FI) in iSCI patients, pointing at the simultaneous decrease in this parameter together with the amplitude depending on the tested lower extremity muscle groups. However, it is difficult to directly confirm the results of our study with the other previously described utilising sEMG methods.