## 3 Results
### Functional Reach Performance Test  
In the reach and return phases of the FRT, no statistically significant differences were observed in the spinal angles between the implant conditions. The implant conditions showed similar mean and standard deviation values compared to the control (Table 4). No statistically significant differences were found in the post hoc analysis of the CoP measurements between implant conditions in the reach and return phases of the FRT. The CoP displacements and velocities showed similar mean values across implant volumes. However, a significant main effect was found in the CoP ML displacement with a power of 0.314 (Table 5). Figure 6: Mean, standard deviation, and \(p\)-values of the sEMG activities of the sternocleidomastoid (SCM) (**a**), erect spinae cervicalis (ESC) (**b**), elevator scapulae (LS) (**c**), pectoralis major (PM) (**d**), upper trapezius (UT) (**e**), lower trapezius (LT) (**f**), lumbar multifidus (LM) (**g**), and transversus abdominis/internal oblique (Tra/IO) (**h**) muscles in the one-minute standing position. Post hoc comparisons with Bonferroni: (i) statistical differences were detected between the control and 220 mL implant condition (mean difference = 0.091; \(p\)-value = 0.003 **); (ii) between the 220 mL implant condition and 315 mL implant condition (mean difference = \(-\)0.106; \(p\)-value = 0.014 *). * \(p\)-value \(<\) 0.05, ** \(p\)-value \(<\) 0.01. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & & & \multicolumn{3}{c}{**Between Conditions Comparisons**} \\  & & & \multicolumn{3}{c}{**F Value (df); \(p\)-Value**} \\
**Variable** & **Condition** & & & **(Observed Power)** \\ \cline{3-5}  & & **Reach** & **Return** & **Reach** & **Return** \\ \hline \multirow{3}{*}{LOM-TRG Angle (\({}^{\circ}\))} & Control & 32.95 (21.94) & 31.97 (21.77) & \multirow{3}{*}{0.431 (3); 0.731} & \multirow{3}{*}{0.227 (2.444); 0.839} \\  & 220 mL & 32.83 (21.28) & 32.37 (21.91) & & \\  & 315 mL & 32.17 (20.87) & 31.48 (20.71) & & (0.134) & (0.088) \\  & 365 mL & 32.49 (20.83) & 31.76 (21.59) & & \\ \hline \multirow{3}{*}{TRG-C7 Angle (\({}^{\circ}\))} & Control & 36.57 (15.22) & 35.85 (14.91) & \multirow{3}{*}{0.502 (2.370); 0.639} \\  & 220 mL & 36.22 (15.92) & 35.60 (15.63) & & \\ \cline{3-5}  & 315 mL & 34.78 (14.25) & 34.69 (14.44) & & (0.442) & (0.137) \\  & 365 mL & 35.34 (15.08) & 35.16 (14.91) & & \\ \hline \multirow{3}{*}{T1-T3-T11-L1 Angle (\({}^{\circ}\))} & Control & 17.86 (6.48) & 14.63 (6.52) & \multirow{3}{*}{0.411 (3); 0.745} & \multirow{3}{*}{0.291 (3); 0.832} \\  & 220 mL & 17.57 (6.10) & 14.53 (7.10) & & \\ \cline{3-5}  & 315 mL & 18.32 (5.70) & 15.01 (6.84) & & (0.129) & (0.104) \\  & 365 mL & 17.99 (5.92) & 14.69 (6.34) & & \\ \hline \multirow{3}{*}{T11-L1-L4-S2 Angle (\({}^{\circ}\))} & Control & 19.11 (8.50) & 19.36 (8.12) & \multirow{3}{*}{0.812} \\  & 220 mL & 19.32 (7.95) & 19.24 (7.16) & & \\ \cline{3-5}  & 315 mL & 18.99 (8.46) & 19.12 (7.49) & & (0.220) & (0.366) \\  & 365 mL & 18.46 (7.35) & 18.30 (6.69) & & \\ \hline \multirow{3}{*}{L4-S2 Angle (\({}^{\circ}\))} & Control & 48.12 (11.44) & 45.53 (10.66) & \multirow{3}{*}{0.856 (3); 0.466} \\  & 220 mL & 47.94 (11.09) & 44.32 (10.72) & & 0.116 (3); 0.950 & 0.856 (3); 0.466 \\ \cline{3-5}  & 315 mL & 47.89 (10.95) & 44.88 (10.04) & & (0.070) & (0.231) \\ \cline{3-5}  & 365 mL & 48.28 (9.57) & 45.13 (10.15) & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Mean and standard deviation (SD) of vertebral column angles of the reach and return phases of the FRT. Statistics of repeated measures ANOVA between implant conditions are included. \begin{table}