## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{3}{*}{**Group/Parameter**} & \multicolumn{5}{c}{**Non-Dominant Leg**} & \multicolumn{2}{c}{**Dominant Leg**} \\  & & \multicolumn{2}{c}{**Taekwondo Fighters**} & \multicolumn{2}{c}{**Control Group**} & \multicolumn{2}{c}{**Control Group**} \\  & & **Um** & **Od** & **Hrv** & **Hfc** & **ToTd** & **ToTd** \\ \hline \multirow{6}{*}{**Cond Group**} & SPtot & 0.417 & 0.772 ** & \(-\)0.618 & \(-\)0.040 & 0.846 * & 0.832 * \\  & SPap & 0.558 & 0.667 * & \(-\)0.678 * & \(-\)0.186 & 0.813 * & 0.789 \\  & SPml & 0.204 & 0.830 ** & \(-\)0.498 & 0.106 & 0.860 * & 0.795 \\  & Aap & 0.624 & 0.635 * & \(-\)0.614 & 0.149 & 0.889 * & 0.804 * \\  & Aml & \(-\)0.004 & 0.641 * & \(-\)0.200 & 0.553 & 0.914 * & 0.750 \\  & Fap & \(-\)0.389 & \(-\)0.320 & 0.232 & \(-\)0.685 & \(-\)0.669 & \(-\)0.597 \\  & Fml & 0.190 & \(-\)0.081 & \(-\)0.133 & \(-\)0.812 ** & \(-\)0.820 * & \(-\)0.597 \\  & SPtot & 0.745 * & 0.504 & \(-\)0.698 & \(-\)0.073 & 0.787 & 0.918 * \\  & SPap & 0.723 * & 0.541 & \(-\)0.695 & \(-\)0.024 & 0.779 & 0.944 * \\  & SPml & 0.762 & 0.469 & \(-\)0.702 & \(-\)0.107 & 0.744 & 0.773 \\  & Aap & 0.800 * & 0.614 & \(-\)0.689 & \(-\)0.021 & 0.786 & 0.945 * \\  & Aml & 0.854 * & 0.507 & \(-\)0.735 & \(-\)0.109 & 0.726 & 0.861 \\  & Fap & \(-\)0.609 & \(-\)0.622 & 0.461 & \(-\)0.094 & \(-\)0.600 & \(-\)0.557 \\  & Fml & \(-\)0.646 & \(-\)0.426 & 0.596 & 0.008 & \(-\)0.477 & \(-\)0.621 \\ \hline \hline \end{tabular} Parameters for which no significant correlations were found were excluded from the table. The following parameters are presented: Hrv—variable error for the Head-to-Neutral Relocation test from right; Hfc—constant error for the Head-to-Neutral Relocation test from flexion; Od—overshoot standard deviation of the Butterfly test; Um—undershoot standard deviation of the Butterfly test; SPtot—distance by the center of pressure movement; SPpal—distance by the center of pressure movement in anterior–posterior direction; SPml—distance by the center of pressure movement in medial–lateral direction; Apa—average amplitude of center of pressure movement in anterior–posterior direction; Aml—average amplitude of center of pressure movement in medial–lateral direction; Fap–average frequency of center of pressure direction changes in anterior–posterior direction; Fml—average frequency of center of pressure direction changes in medial–lateral direction; numbers represent R; \({}^{*}p<0.005\); ** \(p<0.001\).  
\end{table} 
Table 2: Correlations between neck kinesthesia and postural balance. altered in the anterior-posterior direction for sway path and average amplitude. Changes in sway path and average amplitude during neck rotation could indicate different efficiency in maintaining balance control. Although no differences were found in body sway between the legs in taekwondo fighters, there were differences present in the correlation to neck kinesthetic functions. Taekwondo fighters frequently place themselves in an asymmetrical posture. This can induce changes in neck muscle excitability and consequently alter neck muscle proprioception. This speculation is partially confirmed by the results of our study, where variable error in the Head-to-Neutral test from the non-preferred side correlated with average amplitude of body sway in anterior-posterior direction while standing on the non-preferred leg. The active repositioning test has been suggested to be dependent on the sensory drive, primarily from the muscle spindles [17]. Besides amplitude and velocity of the homologues muscle stretch, muscle spindle firing is dependent on the alpha-gamma coactivation controlled by the central nervous system [18]. Altered alpha-gamma coactivation could result in changed excitability of the muscle spindles and consequently their firing properties [18]. Due to possible asymmetrical changes in neck muscle tone, a proprioceptive mismatch could be present in taekwondo fighters, leading to an altered body representation in space [7; 19].