## 3 Results  
From the 68 athletes who agreed to participate in the study, 8 did not meet the inclusion criteria. Thus, a total of 60 semi-professional male athletes (age, 19.7 \(\pm\) 1.9 years; height, 180.6 \(\pm\) 0.1 cm; weight, 74.0 \(\pm\) 9.9 kg; body mass index, 22.6 \(\pm\) 1.9 kg/m\({}^{2}\)), 30 soccer players and 30 basketball players participated in the study. There were no significant differences for age (19.4 \(\pm\) 1.2 versus 20.1 \(\pm\) 2.4, \(p\) = 0.01), height (176.5 \(\pm\) 0.1 versus 184.7 \(\pm\) 0.1, \(p\) = 0.01), weight (67.4 \(\pm\) 7.9 versus 80.7 \(\pm\) 6.7, \(p\) = 0.01), and body mass index (21.6 \(\pm\) 1.3 versus 23.7 \(\pm\) 1.9, \(p\) = 0.01) between soccer and basketball players, respectively. At baseline, there were no statistically significant differences for knee position sense and balance between sessions (Table 2). When comparing the baseline data from first and second sessions (irrespective of the exercise type that followed) we did not find significant differences in any variable; there was no indication of within-session learning effects for joint position sense (AAE 1 st session 1.78 \(\pm\) 1.14\({}^{\circ}\) vs. 2 nd session 1.55 \(\pm\) 1.06\({}^{\circ}\), \(p\) = 0.148), static (BESS 1 st session 7.32 \(\pm\) 2.35\({}^{\circ}\) vs. 2 nd session 7.18 \(\pm\) 2.40\({}^{\circ}\), \(p\) = 0.566) and dynamic (YBT 1 st session 106.6 \(\pm\) 11.7\({}^{\circ}\) vs. 2 nd session 106.4 \(\pm\) 12.5\({}^{\circ}\), \(p\) = 0.689) balance. The reliability of our methods of joint position sense assessment showed an ICC of 0.628 and 0.629 for absolute and relative angular errors between baseline levels of both sessions. Y-balance test and BESS test showed an ICC of 0.969 and 0.835, respectively, between baseline levels of both sessions. \begin{table}
\begin{tabular}{l c} \hline
**Exercise** & **Duration 1** \\ \hline
7. Jump to Bosu with unipodal support & 10 x \\
8. Jump to Bosu with bipodal support with 90\({}^{\circ}\) trunk rotation & 10 x \\
9. Bipodal support in Bosu with eyes closed & 60 s \\
10. Unipodal support in Bosu with eyes closed & 60 s \\ \hline \end{tabular} \({}^{\dagger}\)s—seconds; x—repetitions.  
\end{table} 
Table 1: _Cont._ \begin{table}
\begin{tabular}{c c c c c c c c} \hline  & \multicolumn{3}{c}{**Non-Specific Exercise**} & \multicolumn{3}{c}{**Proprioceptive Exercise**} & \multicolumn{2}{c}{**Comparison between**} \\  & **Before** & **After** & **Difference to** & **Before** & **After** & **Difference to** & **Difference** \\ \hline AAE (\(\cdot\)) & 1.83 \(\pm\) 0.88 & 1.41 \(\pm\) 0.78 * & \(-\)6.9 \(\pm\) 65.2 & 1.71 \(\pm\) 0.81 & 1.22 \(\pm\) 0.81 * & \(-\)11.5 \(\pm\) 75.0 & 4.5\% (\(-\)17.3–26.3) & 0.680 \\ \hline RAE (\(\cdot\)) & 1.21 \(\pm\) 1.69 & 1.01 \(\pm\) 1.36 & 4.7 \(\pm\) 150.6 & 1.08 \(\pm\) 1.62 & 0.85 \(\pm\) 1.29 & \(-\)10.5 \(\pm\) 132.4 & 20.0\% (\(-\)25.0–55.2) & 0.454 \\ \hline \end{tabular}
\end{table} 
Table 2: Pre–post differences in the variables. Both proprioceptive exercise and non-specific exercise sessions significantly improved knee joint position sense (by decreasing absolute angular error) (effect size: 0.51 and 0.47, respectively, for proprioceptive and non-specific), and the performance in the Y-balance test (effect size: 1.00 and 0.95, respectively, for proprioceptive and non-specific) and BESS test (effect size: 1.38 and 0.98, respectively, for proprioceptive and non-specific) (Table 2). There were no statistically significant differences between sessions in the percentage of change in knee position sense and balance, i.e., both sessions induced similar improvements (Table 2). There were no statistically significant differences in relative angular error after both sessions; the participants underestimated the target position before and immediately after both exercise sessions. The results were similar when analyzing soccer and basketball players separately (Table 3).