## 4 Discussion  
The results of this study in patients surgically treated for idiopathic scoliosis confirmed the previous findings in [7], namely, that the transmission of efferent neural impulses in the spinal cord tracts and within the fibers of the peripheral nervous system slightly improves immediately after the surgical correction of scoliosis. Moreover, we ascertained the further normalization of the motor function together with the improvement of TA muscle motor  
Figure 4: Comparison of the amplitude values from mcsEMG (**A**), ENG (**B**), and MEP (**C**) recordings performed on the convex (white bars) and concave (grey bars) sides of the secondary, lumbar curvature in three periods of observation (T0—1 day before surgery, T1—1 week after surgery, and T2—6 months after surgery) in IS patients. unit recruitment half a year after the surgical treatment in IS patients, in which the mcsEMG parameter values are comparable to those of the normal condition. Apart from revealing the improvements regarding biomechanical and aesthetic features of the spine following the applied surgeries for IS patients in clinical studies, the neurophysiological approach enables the investigation of the lateralization of the neurological motor deficits, which are gradually reduced postoperatively, showing almost no difference between the right and left sides during long-term observation. Although the test results referring to the efferent function evaluation presented in Table 2 are consistent and complementary, one can raise the objection that they were shown in patients with IS representing different types of soliotic curvature according to the classification of [PERSON] et al. [27], which might be one of this study's limitations. The patients examined in this study mostly presented type 2 curvature, with the main right-sided curvature of the spine in the thoracic vertebrae and, to a lesser extent, the secondary one with an angle and opposite direction in the lumbar vertebrae, which is excessive in type 3 curvature. These cases are different from the type of scoliosis with an exclusively thoracic angle of curvature occurring in type 1. However, a greater decrease in the amplitude parameter and a slight increase in the latency parameter of MEPs recorded bilaterally in the TA muscle were similarly observed on the concave side of the scoliosis, along with changes in the conductivity of the roots of the lumbar neuromeres, with consequences on the symptoms of neuropathy within the lower limb nerves on the same side. Nevertheless, the possible variations in the pathology patterns that are reflected in the abnormalities found in the functional studies can only be explained by structural MRI studies. The clinical evaluation of the IS patients in this study revealed the changes in the TA muscle strength from a median score of 3-4 in the T0 observation period to 4-5 in T2 at \(p=0.05\), especially on the concave side of the scoliosis. A possible explanation for these discrete differences in the motor performance improvement measured by the clinical method is its low resolution and resulting low precision [31]. However, it is still a widely used and recognized method in clinical practice. This study's neurophysiological methods for assessing motor function are scaled in microvolts and milliseconds. Hence, their results enable the detection of discrete differences in improvements in the neurological status of patients with musculoskeletal dysfunction of various etiologies, including patients with scoliosis. A possible explanation for the immediate improvement of the overall efferent conduction shown in the results of the sEMG, ENG, and MEP studies after IS spinal surgery in the T1 observation period may be the restoration of normal anatomical and functional relationships between the neural structures in the vertebral canal of the deformed spine, mainly through surgical procedures with 3D curvature correction. This applies not only to axons in the lateral and ventral funciuli of the white matter but also to the spinal roots.