# Morphology-Related Foot Function Analysis: Implications for Jumping and Running
## 3 Results  
After calculation and comparison of jump height, there were no significant differences between the height of the barefoot jump (\(386.4\pm 13.6\) mm) and shod jump (\(408.2\pm 12.9\) mm), with \(p>0.05\). As shown in Figure 1, during the take-off phase (left), significant differences (\(p<0.05\)) were found between barefoot and shod jumping in H (\(p=0.02\) and \(0.01\)), MF (\(p=0.018\) and \(0.029\)), and CF (\(p=0.026\) and \(0.03\)) for peak pressure and the pressure-time integral. Significance for the contact area was also found in H (\(p=0.032\)). Figure 1: The peak pressure, pressure time integral, and contact area in the anatomical regions during the push-off (**a**) and landing (**b**) phases of the vertical jump. lateral forefoot (LF), central forefoot (CF), medial forefoot (MF), hallux (H), and other toes (OT). * indicates significance between variables, \(p<0.05\). During the landing phase (right), significant differences were found between barefoot and shod jumping in H (\(p\) = 0.016 and 0.021), MF (\(p\) = 0.026 and 0.031), and CF (\(p\) = 0.04 and 0.033) for peak pressure and the pressure time integral. For contact area, significant differences were found in H (\(p\) = 0.034) and CF (\(p\) = 0.02). As measured from the running test, participants' running speeds were self-selected as comfortable from the generated spatiotemporal parameter. The comparison of collected spatiotemporal parameters, including stride length, stride time, and contact time, in one gait cycle between barefoot and shod running, are presented in Table 1.  
As shown in Figure 2, the stances of barefoot and shod running were highlighted with solid (\(33.2\pm 0.7\%\)) and dashed (\(37.5\pm 0.8\%\)) vertical lines, which were calculated from the percentage of contact time in stride time. The peak angles during the stance were thus obtained between barefoot and shod running, and statistical significance was highlighted with a red dotted line with an asterisk (*), with Table 2 presenting detailed values. There was a significant difference between the foot strike angle of the ankle between shod and barefoot running, with the foot strike angle of shod running at \(17.1\pm 4.3^{\circ}\), and barefoot running at \(-7.2\pm 3.9^{\circ}\) (minus indicates plantar flexion), \(p\) = 0.00. Internal and external ankle rotation also showed a significant difference, \(p\) < 0.05. The maximal rotation angle during the push-off phase of the \begin{table}
\begin{tabular}{c c c c} \hline  & **Stride Length (m)** & **Stride Time (s)** & **Contact Time (s)** \\ \hline
**Barefoot** & \(2.35\pm 0.19\)\({}^{*}\) & \(0.76\pm 0.027\)\({}^{*}\) & \(0.252\pm 0.018\)\({}^{*}\) \\
**Shod** & \(2.46\pm 0.21\) & \(0.794\pm 0.032\) & \(0.298\pm 0.013\) \\ \hline \end{tabular} Note: * Significance between barefoot and shod runners, \(p\) < 0.05.  
\end{table} 
Table 1: The spatiotemporal parameters between barefoot and shod running. Figure 2: Joint angles curves of the ankle, knee, and hip in sagittal, frontal, and horizontal planes during one gait cycle. Red dotted lines with * indicate a significant difference, \(p\) < 0.05.  
stance was \(3.24\pm 2.26^{\circ}\) (shod running) and \(-3.76\pm 1.5^{\circ}\) (barefoot running). Barefoot running showed significantly larger ankle ROM than shod running, \(p=0.00\) (Table 3). The knee joint contact angles while foot landing were \(12.33\pm 8.45^{\circ}\) (shod) and \(0.1\pm 2.3^{\circ}\) (barefoot), showing significance (\(p=0.012\)) (highlighted in Figure 2). Smaller knee joint ROM in the sagittal plane was also observed, with \(p=0.021\) (Table 3). For hip movement, shod running (\(38.79\pm 7.81^{\circ}\)) presented a larger flexion angle than barefoot running (\(30.12\pm 5.66^{\circ}\)) while landing (\(p=0.03\)) (Table 2). A greater internal rotation angle was observed for barefoot running (\(27.21\pm 3.66^{\circ}\)) than shod running (\(14.21\pm 2.66^{\circ}\)), as the foot was landing (\(p=0.32\)) (Figure 2). Shod running presented significantly larger ROM than barefoot running in the gait cycle (Table 3).