## 3 Results  
### Descriptive Statistics, Symmetry and Jaccard Indices (SI and JI)  
The descriptive statistics and symmetry indices for the independent variables (skiing technique and ground reaction forces) and dependent variables (skiing performance) during skiing are presented in Tables 1 and 2, respectively. In most cases, the differences in the independent variables during left and right turns were statistically insignificant (Table 1), the exception being GRF on the entire inside foot (\(p<0.05\)). The mean symmetry indices (SI) for the independent variables related to skiing technique ranged from approximately 92 to 98%, with associated Jaccard indices (JI) during the steering phase ranging from approximately 29 to 53%. The corresponding values for the independent variables related to GRF ranged from approximately 85 to 98% and approximately 42 to 71%, respectively. Moreover, none of the values for the dependent variables reflecting skiing performance differed significantly between the left and the right turns (Table 2). The mean SI for the dependent variables ranged from approximately 71% (in the case of instantaneous performance) to approximately 100% (average velocity). The nature of the parameters involved allowed the JI values to be calculated only for the turning radius and instantaneous performance during the steering phase as approximately 56% and 47%, respectively. The patterns of the angle of the outside shank of all nine skiers during left and right turns, together with the corresponding JI during the steering phase (ranging from 14% for Skier I to 87% for Skier G), are shown in Figure 4. As depicted in the diagram, the mean angle of the outside shank during left and right turns differed during the entire steering phase for Skiers H and I, during the second half of the steering phase for Skiers B, D and E and during the first half of this phase in the case of Skier A. In contrast, the mean angle of the outside shank of Skier G was largely the same throughout the \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Variable** & **Left Turn** & **Right Turn** & \(p\)**-Value** & **SI [\%]** & **JI [\%]** \\ \hline
**Shank angle[ \({}^{\circ}\)]** & & & & & \\ \hline
**Outside leg** & \(30.8\pm 4.5\) & \(29.4\pm 4.6\) & 0.49 & \(93.8\pm 5.4\) & \(52.2\pm 19.5\) \\
**Inside leg** & \(33.2\pm 3.8\) & \(34.2\pm 2.4\) & 0.84 & \(92.8\pm 4.0\) & \(41.5\pm 16.2\) \\
**Knee flexion[ \({}^{\circ}\)]** & & & & & \\ \hline
**Outside leg** & \(46.99\pm 8.9\) & \(52.20\pm 7.2\) & 0.11 & \(92.5\pm 4.4\) & \(28.7\pm 24.3\) \\
**Inside leg** & \(85.73\pm 9.3\) & \(81.25\pm 9.9\) & 0.34 & \(96.1\pm 2.2\) & \(39.1\pm 21.7\) \\ Hip flexion[ \({}^{\circ}\)] & & & & & \\ \hline
**Outside leg** & \(37.4\pm 3.3\) & \(28.02\pm 3.0\) & 0.70 & \(95.71\pm 2.2\) & \(53.35\pm 14.9\) \\
**Inside leg** & \(71.8\pm 4.4\) & \(68.79\pm 5.5\) & 0.22 & \(97.52\pm 1.7\) & \(50.64\pm 15.5\) \\
**GRF (pressure insoles)[ \% BW]** & & & & & \\ \hline
**On the entire foot** & & & & & \\ \hline
**Outside leg** & \(126.2\pm 19.2\) & \(113.6\pm 21.6\) & 0.21 & \(92.9\pm 4.7\) & \(56.1\pm 18.9\) \\
**Inside leg** & \(66.8\pm 7.4\) & \(76.0\pm 10.0\) & 0.04 & \(91.4\pm 5.7\) & \(56.0\pm 19.6\) \\
**On the fore foot[ \% BW]** & & & & & \\ \hline
**Outside leg** & \(62.5\pm 20.6\) & \(58.7\pm 26.85\) & 0.75 & \(88.4\pm 8.4\) & \(47.2\pm 21.6\) \\
**Inside leg** & \(27.4\pm 9.2\) & \(37.8\pm 17.6\) & 0.14 & \(85.1\pm 10.1\) & \(42.7\pm 23.2\) \\
**On the rear foot[ \% BW]** & & & & & \\ \hline
**Outside leg** & \(63.8\pm 7.7\) & \(54.9\pm 16.6\) & 0.17 & \(87.8\pm 7.3\) & \(51.6\pm 14.4\) \\
**Inside leg** & \(39.4\pm 9.13\) & \(38.6\pm 15.8\) & 0.85 & \(85.8\pm 15.2\) & \(52.9\pm 23.2\) \\
**GRF *** & & & & & \\
**Overall [\% BW]** & \(287.5\pm 26.3\) & \(283.7\pm 17.5\) & 0.72 & \(98.2\pm 1.1\) & \(71.3\pm 2.7\) \\ \hline \hline \end{tabular}  
* BW—body weight; SI—symmetry index; JI—Jaccard index;
* approximated on the basis of the movement of the center of mass.  
\end{table}