## 3 Results  
Before TRS, the CP group walked at significantly decreased speed with increased step width when compared to Control. TRS tended to increase the gait speed in the CP group, with significantly increased stride time and decreased cadence (\(p<0.05\)) as compared to Control (Table 1). No significant differences in time-averaged values of \(K_{L}\) and \(K_{T}\) over LR and PS were found between CP and Control (Table 2). In the healthy Controls, the limb shared greater \(K_{T}\) during LR than during PS (Figures 3 and 4a,b). Compared to Control, the CP group showed significantly decreased \(K_{S}\) during LR but increased \(K_{S}\) during PS before surgery (Pre-OP) (Table 2), resulting in similar \(K_{S}\) between LR and PS within the CP group (Figures 3 and 4a,b, Table 2). After surgery, the CP group showed significantly greater \(K_{S}\) during LR than during PS (Figures 3 and 4a,b, Table 2). Compared to Control, the CP group showed significantly increased SI values during MS, TS and PS phases before TRS (Pre-OP). Generally, TRS tended to reduce the SI values during MS, TS and PS, reaching statistical significance for TS (Table 3). After TRS, no significant differences in SI between Control and CP (Post-OP) were found throughout the whole gait cycle (Table 3). Figure 2: Schematic illustration of the gait cycle. Figure 4: _Cont._  
Figure 3: Means and standard deviations (error bars) of the proportional shares (%) of total leg stiffness (\(K\)s) between phases of loading response (LR, dark gray) and pre-swing (PS, light gray) of gait for the Control and CP group before TRS (Pre-OP) and after TRS (Post-OP). \(p\)-values of the pair-wise comparisons in Ks are also given. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Group** & **Leg Length** & **Cadence** & \begin{tabular}{c} **Normalized** \\ **(Steps/min)** \\ \end{tabular} & \begin{tabular}{c} **Stride Time (s)** \\ **(m/s-m)** \\ \end{tabular} & \begin{tabular}{c} **Normalized** \\ **Stride Time (s)** \\ \end{tabular} & \
\begin{tabular}{c} **Normalized** \\ **Stride Length (m/m)** \\ \end{tabular} &
\begin{tabular}{c} **Step Width (m)** \\ \end{tabular} \\ \hline Con & 0.74 (0.08) & 120.4 (13.2) & 1.22 (0.59) & 1.01 (0.12) & 0.73 (0.08) & 0.10 (0.03) \\ Pre-OP & 0.67 (0.12) & 110.4 (27.4) & 0.85 (0.31) & 1.16 (0.29) & 0.77 (0.22) & 0.16 (0.07) \\ Post-OP & 0.67 (0.11) & 102.3 (15.5) & 0.93 (0.19) & 1.22 (0.21) & 0.82 (0.20) & 0.17 (0.08) \\ \(p\) (Con vs. Pre-OP) & 0.12 & 0.31 & \textless{}0.01 * & 0.16 & 0.59 & 0.02 * \\ \(p\) (Con vs. Post-OP) & 0.10 & 0.01 * & \textless{}0.01 * & 0.01 * & 0.20 & 0.01 * \\ \(p\) (Pre-OP vs. Post-OP) & 1.00 & 0.23 & 0.47 & 0.31 & 0.54 & 0.83 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Means (standard deviations) of the gait temporal-spatial parameters for the CP group (Pre-OP: before surgery; Post-OP: after surgery) and the Control group (Con). Figure 4: (a) Leg stiffness of the ipsilateral (black) and contralateral limb (gray), and (b) total leg stiffness during stance phase of gait for the Control group (dashed) and CP group before TRS (thick) and after TRS (thin). The vertical lines around 20% stance phase indicate the contralateral toe-off or the end of the initial double-limb support (DLS), while those around 80% stance phase indicate the contralateral heel-strike or the end of single-limb support (SLS) or the beginning of terminal DLS.