# Comparison of Gait Smoothness Metrics in Healthy Elderly and Young People
## 3 Results
Each of these bar diagrams corresponds to the smoothness values calculated for the normal gait task, showcasing comparisons between the younger (orange) and elderly (blue) participant groups. In further detail, the four pairs of bars represent the analyzed signals across three directional components (V, ML and AP), along with the corresponding root mean square (RMS) values derived from these signals. Similarly, Figures 4 and 5 provide visual representations of the same comparison but specifically associated with the fast-walking task. These figures delineate the differences in smoothness between the age groups for both gait conditions. Conversely, Figures 6-9 detail the variations in smoothness behavior within the same groups of subjects based on the velocities of the walking task. Figures 6 and 8 exhibit smoothness values for accelerations during the normal gait task (depicted in blue) and the fast-walking task (depicted in orange) using the three metrics. In contrast, Figures 7 and 9 represent angular velocities, illustrating the respective smoothness values during the normal and fast-walking tasks for the same age groups. The symbol * above the two compared bars denotes a difference between the compared values. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**HR** & & **Young** & **Older** & \\ \hline \multirow{3}{*}{Acc-V} & Normal & 1.51 (0.40) & 1.20 (0.13) & \(\mathbf{p=0.0070}\) \\  & Fast & 1.98 (0.49) & 1.23 (0.17) & \(\mathbf{p<0.0001}\) \\  & & \(\mathbf{p=0.0038}\) & \(\mathbf{p=0.1208}\) & \\ \hline \multirow{3}{*}{Acc-ML} & Normal & 0.85 (0.14) & 1.00 (0.08) & \(\mathbf{p=0.0056}\) \\  & Fast & 1.02 (0.12) & 0.95 (0.07) & \(\mathbf{p=0.1011}\) \\  & & \(\mathbf{p=0.0061}\) & \(\mathbf{p=0.0340}\) & \\ \hline \multirow{3}{*}{Acc-AP} & Normal & 1.07 (0.25) & 1.26 (0.16) & \(\mathbf{p=0.0226}\) \\  & Fast & 1.27 (0.22) & 1.19 (0.13) & \(\mathbf{p=0.2351}\) \\  & & \(\mathbf{p=0.0016}\) & \(\mathbf{p=0.0299}\) & \\ \hline \multirow{3}{*}{Acc RMS} & Normal & 1.65 (0.46) & 1.21 (0.13) & \(\mathbf{p<0.0001}\) \\  & Fast & 2.11 (0.51) & 1.25 (0.17) & \(\mathbf{p<0.0001}\) \\  & & \(\mathbf{p=0.0072}\) & \(\mathbf{p=0.1788}\) & \\ \hline \multirow{3}{*}{Gyr-V} & Normal & 0.72 (0.12) & 1.15 (0.07) & \(\mathbf{p<0.0001}\) \\  & Fast & 1.01 (0.24) & 1.08 (0.08) & \(\mathbf{p=0.4178}\) \\  & & \(\mathbf{p<0.0001}\) & \(\mathbf{p=0.0045}\) & \\ \hline \multirow{3}{*}{Gyr-ML} & Normal & 0.72 (0.17) & 0.90 (0.10) & \(\mathbf{p=0.0039}\) \\  & Fast & 0.94 (0.25) & 0.81 (0.11) & \(\mathbf{p=0.1366}\) \\  & & \(\mathbf{p=0.0200}\) & \(\mathbf{p=0.0023}\) & \\ \hline \multirow{3}{*}{Gyr-AP} & Normal & 0.80 (0.11) & 1.14 (0.13) & \(\mathbf{p<0.0001}\) \\  & Fast & 1.00 (0.06) & 1.07 (0.12) & \(\mathbf{p=0.0523}\) \\  & & \(\mathbf{p<0.0001}\) & \(\mathbf{p=0.0627}\) & \\ \hline \multirow{3}{*}{Gyr RMS} & Normal & 0.87 (0.13) & 1.26 (0.11) & \(\mathbf{p<0.0001}\) \\  & Fast & 1.26 (0.27) & 1.18 (0.07) & \(\mathbf{p=0.4624}\) \\ \cline{1-1}  & & \(\mathbf{p<0.0001}\) & \(\mathbf{p=0.0072}\) & \\ \hline \hline \end{tabular} \(p\)-values below the 0.05 significant threshold were marked in bold.  
\end{table} 
Table 5: Smoothness of gait calculated through HR for the two age groups at two different speeds with the respective statistical difference \(p\)-values. \(p\)-values reported below the group column refer to intra-group comparison, while \(p\)-values reported on the right column refer to inter-group comparison. Values are expressed as mean (standard deviation). Figure 4: Smoothness of the acceleration signals along vertical (V), mediolateral (ML) and anteroposterior (AP) directions and acceleration RMS during the self-selected fast speed gait task. (**a**) Older vs. young implemented with LDLJ; (**b**) older vs. young implemented with SPARC; (**c**) older vs. young implemented with HR. * Specifies statistical difference in the comparison.