## 3 Results
### Impact Perception  
Results of the Spearman correlation indicated that there was a significant positive correlation of low strength between perceived landing impact and rearfoot vertical peak force, (r\({}_{8}\)(106) = 0.323,  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Drop**} & \multicolumn{2}{c}{**Midsole Hardness**} & \multicolumn{6}{c}{**ANOVA**} \\ \cline{3-13}  & **Height** & \multicolumn{3}{c}{**Height**} & \multicolumn{3}{c}{**Hardness**} & \multicolumn{3}{c}{**Interaction**} \\ \cline{3-13}  & **[cm]** & **50 Asker C** & **60 Asker C** & \(p\) & \(\eta_{p}\)\({}^{2}\) & \(\beta\) & \(p\) & \(\eta_{p}\)\({}^{2}\) & \(\beta\) & \(p\) & \(\eta_{p}\)\({}^{2}\) & \(\beta\) \\ \hline GM & 31 & 5.69 (21.8) & 6.56 (4.74) & & & & & & & & & \\
[mV] & 46 & 5.87 (2.31) & 5.60 (1.87) & **0.003*** & 0.338 & 0.903 & 0.994 & 0.000 & 0.050 & 0.325 & 0.077 & 0.235 \\
[mV] & 61 & 8.31 (2.90) & 7.70 (2.44) & & & & & & & & \\ \hline BF & 31 & 12.71 (12.43) & 11.99 (13.57) & & & & & & & & \\
[mV] & 46 & 12.95 (14.32) & 14.05 (16.69) & **0.001*** & 0.332 & 0.950 & 0.936 & 0.000 & 0.051 & 0.391 & 0.054 & 0.203 \\
[mV] & 61 & 16.81 (14.55) & 16.55 (15.07) & & & & & & & & \\ \hline RF & 31 & 20.45 (8.62) & 20.48 (8.23) & & & & & & & & \\
[mV] & 46 & 25.54 (9.85) & 23.76 (9.93) & **+0.001*** & 0.721 & 1.000 & **0.042** & 0.221 & 0.544 & 0.192 & 0.093 & 0.338 \\
[mV] & 61 & 35.65 (14.71) & 32.36 (13.05) & & & & & & & & & \\ \hline VM & 31 & 33.45 (12.55) & 34.14 (16.91) & & & & & & & & & \\
[mV] & 46 & 45.65 (22.00) & 48.36 (25.31) & **+0.001*** & 0.511 & 0.997 & 0.374 & 0.047 & 0.139 & 0.793 & 0.014 & 0.084 \\
[mV] & 61 & 66.90 (37.15) & 67.05 (38.42) & & & & & & & & & \\ \hline MG & 31 & 81.48 (37.84) & 88.24 (41.72) & & & & & & & & & \\
[mV] & 46 & 10.107 (35.35) & 95.05 (45.4) & **0.001*** & 0.361 & 0.948 & 0.504 & 0.030 & 0.098 & 0.130 & 0.127 & 0.411 \\
[mV] & 61 & 99.33 (45.69) & 103.09 (49.73) & & & & & & & & & \\ \hline Sol & 31 & 37.54 (17.83) & 43.12 (10.99) & & & & & & & & & \\
[mV] & 46 & 51.83 (18.69) & 59.33 (23.56) & **+0.001*** & 0.455 & 0.995 & 0.417 & 0.039 & 0.123 & 0.072 & 0.144 & 0.522 \\
[mV] & 61 & 81.94 (40.07) & 78.09 (44.4) & & & & & & & & & \\ \hline TA & 31 & 39.90 (19.86) & 35.46 (23.63) & & & & & & & & & \\
[mV] & 46 & 46.34 (25.56) & 43.11 (27.13) & **0.003*** & 0.296 & 0.910 & **0.043** & 0.220 & 0.542 & 0.597 & 0.03 & 0.129 \\
[mV] & 61 & 51.87 (26.80) & 45.05 (25.81) & & & & & & & & & \\ \hline \hline \end{tabular} Notes: GM = gluteurs maximum; BF = biceps femoris; RF = rectus femoris; VM = vastus medialis; MG = medial gastrocnemius; Sol = soleus; TA = tibialis anterior. Three participants were removed from statistical analysis for GM (N = 15) and two for MG (N = 16) muscles due to signal errors. Significant \(p\)-values (\(p<0.05\)) are shown in bold. Effect size (partial eta-squared, \(\eta_{p}\)\({}^{2}\)) was interpreted as small (\(0.01<\eta_{p}\)\({}^{2}\)\(\leq 0.09\)), medium (\(0.09<\eta_{p}\)\({}^{2}\)\(\leq 0.25\)), or large (\(\eta_{p}\)\({}^{2}\)\(>0.25\)); \(\beta\) denotes observed power. * Significant difference between 31-cm and 46-cm drop height. * Significant difference between 46-cm and 61-cm drop height. * Significant difference between 31-cm and 61-cm drop height.  
\end{table}
Table 4: Platform height and midsole hardness effects on mean muscle activation of lower limb muscles during the precontact phase of drop vertical jumps.  
Figure 3: Mean (\(\pm\) standard deviation) muscle activation of the rectus femoris (RF) and tibialis anterior (TA) muscles versus time during the preparation phase (100 ms before initial contact) of drop vertical jumps performed from various heights in shoes with soft (blue line) and hard (red blue) midsoles.  
\(p<0.001\), Figure 4). Forefoot and rearfoot vertical force loading rate each had a positive but negligible association with perceived landing impact (\(\rm{r_{s}}(106)=0.190\), \(p=0.049\); \(\rm{r_{s}}(106)=0.226\), \(p=0.019\), respectively).