## 3 Results  
Frailty was identified in 37 (28%) participants, prefrailty in 66 (50%), and no criteria were found in 30 (23%) participants. Demographic and clinical characteristics are shown in Table 1.  
Post-hoc comparisons using the Tukey HSD test indicated that the mean scores of age, calf circumference, PASE and FES-I scores for the frailty group were significantly different from the prefrailty and robust groups, and the number of medications between prefrailty and frail groups. We did not find any significant differences in gender (Table 2), MMSE score, BMI, comorbidities between these three groups. Frail participants were significantly older, they had a smaller calf circumference, had a higher proportion of fallers, and higher FES-I scores, while prefrail subjects had a higher fear of falling prevalence (Table 2) than in other groups. Compared to prefrail individuals, frail individuals had a significantly higher prevalence of weak hand grip strength and weight loss criteria. The comparison of scores of physical performance tests and sensor-derived gait parameters between three frailty groups is presented in Table 3.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{Characteristic\({}^{\circ}\)+} & \multirow{2}{*}{Total Sample \(\mathbf{(n=133)}\)} & \multirow{2}{*}{Robust} & \multirow{2}{*}{Prétial} & \multirow{2}{*}{Prétial} & \multirow{2}{*}{Prétial} & \multirow{2}{*}{Prétial} & \multirow{2}{*}{Prétial} \\  & & & & & & & & \\  & **(n=133)** & **(n=20)  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Variable \({}^{*}\)** & \begin{tabular}{c} **Total Sample** \\ **(n = 133)** \\ \end{tabular}  & \begin{tabular}{c} **Robust** \\ **(n = 30)** \\ \end{tabular}  & \begin{tabular}{c} **Prefail** \\ **(n = 66)** \\ \end{tabular}  & \begin{tabular}{c} **Frail** \\ **(n = 37)** \\ \end{tabular}  & \begin{tabular}{c} **\(p\) Value \({}^{*}\)** \\ \end{tabular}  & \ \begin{tabular}{c} **Partial** \\ **(F)** \\ \end{tabular}  &
\begin{tabular}{c} **\(p\) Value \({}  
All the comparisons revealed statistically significant differences, except the DGI score and swing phase time between prefrail and frail subjects (effect size indicated by the partial eta squared is medium). Gait velocity best discriminated robust versus frail participants (partial \(\eta_{i}^{2}=0.374\)), whereas the second best discriminator was cadence (partial \(\eta_{i}^{2}=0.329\)). When comparing the means of stride time, stance phase and swing phase time on the left and right leg, we obtained identical results, so only the parameters from the right leg were used for this and further analyses. The results of multinomial logistic regression are presented in Table 4. All the evaluated variables were able to discriminate between prefrail and robust and frail and robust levels with statistically significant differences. TUG time, stride, stance time in milliseconds, swing and stance phases normalized to a percentage of gait cycle, and double support time increased the odds of being prefrail versus robust and frail versus robust, whereas a higher DGI score, gait velocity, and cadence decreased the odds. Table 5 shows the sensitivity and specificity of different gait parameters when used to identify the frail and prefrail populations and their cut-offs. All the variables had higher validity to separate prefrail or frail from robust (AUC = \(0.735-0.969\)) than frail from prefrail or robust (AUC = \(0.675-0.810\)). Among gait parameters, other than gait speed, stride time (AUC = \(0.915\)), stance phase time (AUC = \(0.923\)), and cadence (AUC = \(0.930\)) were the best discriminators to separate frail or prefrail from robust. Other gait parameters, such as stance phase, normalized in percent of gait cycle, and double support time had sufficient validity to separate prefrail or frail from robust, although both had poor