## 4 Discussion  
The current study aimed to quantify the effects of LS on the whole-body balance control during level walking by comparing the IA and RCIA with those of healthy controls,  
Figure 3: Ensemble-averaged curves of the COM–COP inclination angle (IA) and rate of change of IA (RCIA) in the frontal plane during level walking in patients with lumbar spondylosis (solid line) and healthy controls (dashed line). \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{4}{c}{**COM–COP Inclination Angle (RCIA, \({}^{\circ}\)/s) of LS**} \\ \hline
**Variables** & **DCOP** & \(\mathbf{p}\)**-Value** & **ACOP** & \(\mathbf{p}\)**-Value** \\ \hline \multicolumn{5}{c}{Sagittal Plane: Anterior (+)/Posterior (-)} \\ HS & 0.19 & 0.583 & 0.09 & 0.798 \\ TO & 0.46 & 0.156 & 0.14 & 0.687 \\ Time-averaged & & & & \\ DLS & \(-\)0.08 & 0.818 & 0.50 & 0.115 \\ SLS & 0.48 & 0.132 & \(-\)0.39 & 0.234 \\ Ranges & & & & \\ DLS & 0.38 & 0.256 & 0.07 & 0.841 \\ SLS & \(-\)0.57 & 0.065 & \(-\)0.18 & 0.607 \\ \hline \multicolumn{5}{c}{Frontal Plane: Medial (+)/Lateral (-)} \\ HS & \(-\)0.34 & 0.313 & 0.21 & 0.531 \\ TO & 0.42 & 0.203 & 0.13 & 0.710 \\ Time-averaged & & & & \\ DLS & \(-\)0.11 & 0.754 & \(-\)0.08 & 0.821 \\ SLS & 0.51 & 0.111 & 0.00 & 0.999 \\ Ranges & & & & \\ DLS & 0.04 & 0.908 & 0.78 & 0.005 * \\ SLS & \(-\)0.53 & 0.094 & 0.22 & 0.509 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: [PERSON]’s correlation coefficient (r) between IA during gait, COP total distance (DCOP), and sway area (ACOP) during quiet standing in the lumbar spondylosis group (LS). HS: heel-strike; TO: toe-off; DLS: double-limb support; SLS: single-limb support; *: significant correlation (\(p\) < 0.05). and to identify the possible correlations between the IA and RCIA during gait and the DCOP and ACOP during quiet standing in the LS group. The patients with LS were found to walk with a conservative and cautious strategy for dynamic balance control in the sagittal plane, maintaining a more posterior COM position relative to the COP with reduced ranges and speed of movement throughout the gait cycle, as well as a slower body weight transfer during DLS. In the frontal plane, the patients moved the COM more medially with greater velocity changes during weight transfer, indicating less stable transfer of the body weight in the medial-lateral direction. Standing balance parameters were found to predict IA and RCIA deviations during DLS in the frontal plane, possibly because the standing balance tests were also performed in the double-limb support posture. However, standing balance parameters failed to predict the IA and RCIA deviations during SLS in the frontal plane and the RCIA deviations throughout the gait cycle in the sagittal plane. These correlational results suggest that dynamic balance control deviations during gait in patients with LS could not be deduced solely from data gathered from standing balance tests, and thus patients should be monitored via dynamic approaches in clinical applications. In the sagittal plane, during SLS the COM travels from a trailing position towards the stance foot, over the stance foot, and then to a leading position, over a much greater distance than that of the COP underneath the stance foot. Compared to the healthy controls, the patients showed a smaller anterior RCIA and smaller ranges of IA and RCIA, indicating that their COM traveled a shorter distance more slowly when moving over the stance foot [18]. This strategy is helpful for a smooth inverted pendulum motion of the body in the sagittal plane [27, 48]. In contrast, during DLS, the COM movement was smaller than during SLS, and the changes of the IA and RCIA were largely accounted for by the COP which traveled from the trailing weight-release limb to the leading weight-acceptance limb. Increasing the DLS time and the stride time would help to smooth the weight transfer, and thus stabilize the whole-body balance control, but this will reduce the gait speed.