## 3 Results
### Effect of DPN on Foot Joints ROM and Gait Kinematics  
ANCOVA analysis revealed several significant differences in ROM between DPN, non-DPN and controls by accounting also for the effect of normalized walking speed, age and BMI (Table 4). In the sagittal plane, the midtarsal and tarsometatarsal joints and the metatarasus to calcaneus rotation had significantly lower ROM in DPN and non-DPN with respect to controls (\(p<0.05\)). While no significant differences were observed between DPN and non-DPN, frontal-plane ROM of the midtarsal joint in non-DPN was significantly lower than control. The metatarasus to calcaneus transverse-plane rotation presented significantly lower ROM in DPN and non-DPN with respect to controls (\(p<0.01\)). A reduction in motion in DPN and non-DPN was also observed between leg and foot in the sagittal and transverse planes. Figure 2: Mean temporal profiles of foot joint rotations [deg] normalized to gait cycle duration across all trials of type 1 (continuous blue line) and type 2 diabetes (dashed blue line), and control subjects (continuous black line). Top to bottom, rotation in the three anatomical planes between calcaneus and shank (ShCa), midfoot and calcaneus (CaMi), metatarasus and midfoot (MiMe), and metatarasus and calcaneus (CaMe). Left to right, rotations in the sagittal, frontal and transverse planes according to the axes of each joint coordinate system. Figure 3: Outcomes of the SPM two-tailed paired t-tests which allowed to identify supra-threshold clusters of SPM (t) for the pairwise comparisons between temporal profiles of joint rotations in type 1, type 2 and control groups. Time intervals of statistically significant differences (\(p<0.05\)) between groups are shown in grey. Regarding the SPM analysis, while some offset was present between groups, most foot joints had similar temporal patterns of rotations across DPN, non-DPN and control subjects for most of the normalized gait cycle (Figures 4 and 5). In the sagittal plane, DPN and non-DPN midtarsal joint was more dorsiflexed across the whole gait cycle with respect to controls (\(p<0.001\)). Conversely, the tarsometatarsal joint was more plantarflexed across the whole gait cycle. As to the metatarsus to calcaneus sagittal plane rotation, one supra-threshold cluster (55-65% of gait cycle) exceeded the critical threshold as the CaMe pair in both DPN and non-DPN was significantly more dorsiflexed than in controls (\(p<0.05\)). In the frontal plane, the tarsometatarsal joint of DPN and non-DPN was significantly more inverted than in controls throughout the whole gait cycle (\(p<0.001\)). In the transverse plane, the midtarsal joint of both DPN and non-DPN was significantly more adducted than in controls for most of the gait cycle. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline  & & \multicolumn{2}{c}{**DPN**} & \multicolumn{2}{c}{**Non-DPN**} & \multicolumn{2}{c}{**Control**} & \multicolumn{2}{c}{**DPN vs. Non-DPN**} \\  & & **\multicolumn{1}{c}{**vs. Control**} & \multicolumn{1}{c}{**vs. Control**} \\ \hline
**Joint** & **Plane** & **Mean** & **STD** & **Mean** & **STD** & **Mean** & **STD** & \\ \hline \multirow{3}{*}{**ShFo**} & Sagittal & 21.4 & 4.0 & 22.2 & 3.5 & 25.2 & 3.4 & Control \textgreater{} DPN Control \textgreater{} \\  & Frontal & 12.8 & 3.0 & 11.7 & 3.2 & 11.9 & 2.3 & \multirow{3}{*}{Control \textgreater{} DPN Control \textgreater{} \textgreater{} \textgreater{} \texttextgreater{}  
Figure 4: Mean temporal profiles of foot joint rotations [deg] normalized to gait cycle duration across all trials of neuropathic (DPN, continuous red line), non-neuropathic (non-DPN, dashed red line) and control subjects (continuous black line). Top to bottom, rotation in the three anatomical planes between calcaneus and shank (ShCa), midfoot and calcaneus (CaMi), metatarasus and midfoot (MiMe) and metatarasus and calcaneus (CaMe). Left to right, rotations in the sagittal, frontal and transverse planes according to the axes of each joint coordinate system.