## 2 Materials and Methods
### Testing Procedure  
Volunteers visited the department's physical therapy facilities on two separate occasions. During the first visit, anthropometric measurements, including body mass and height, were recorded. Additionally, a comprehensive musculoskeletal assessment was  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Side** & \multicolumn{2}{c}{**Groups**} \\ \hline  & **HFT (n = 21)** & **NFT (n = 21)** & **Total (n = 42)** \\ \hline Sex (M/F) & 11/10 & 11/10 & 22/20 \\ Age (yrs) & 24.4 \(\pm\) 2.7 & 23.8 \(\pm\) 3.1 & 24.1 \(\pm\) 2.9 \\ Body Mass (kg) & 71.0 \(\pm\) 14.3 & 68.5 \(\pm\) 9.7 & 69.8 \(\pm\) 12.1 \\ Height (m) & 1.7 \(\pm\) 0.1 & 1.7 \(\pm\) 0.1 & 1.7 \(\pm\) 0.1 \\ Body Mass Index (kg\(\cdot\)m\({}^{-1}\)) & 20.5 \(\pm\) 3.3 & 19.9 \(\pm\) 2.3 & 20.2 \(\pm\) 2.9 \\ FPI-6 score & R & 10.6 \(\pm\) 1.1 & 2.4 \(\pm\) 1.5 \({}^{**}\) & 6.5 \(\pm\) 4.3 \\ L & 10.5 \(\pm\) 0.9 & 2.6 \(\pm\) 1.3 \({}^{**}\) & 6.5 \(\pm\) 4.2 \\ Leg length & R & 88.7 \(\pm\) 6.1 & 87.0 \(\pm\) 4.0 & 87.8 \(\pm\) 5.1 \\ L & 88.7 \(\pm\) 6.1 & 87.0 \(\pm\) 4.1 & 87.8 \(\pm\) 5.2 \\ Ankle dorsi flexion (\({}^{\circ}\)) & R & 53.8 \(\pm\) 5.1 & 50.0 \(\pm\) 6.0 \({}^{**}\) & 51.9 \(\pm\) 5.8 \\  & L & 53.6 \(\pm\) 5.5 & 50.0 \(\pm\) 5.8 \({}^{**}\) & 51.8 \(\pm\) 5.9 \\ \hline \hline \end{tabular} Note: HFT = hyperpronated foot type; NFT = neutral foot type; \({}^{*}\)_p_ < 0.05; \({}^{**}\)_p_ < 0.001.  
\end{table}
Table 1: Means \(\pm\) standard deviations of anthropometric measurements of the study sample in individuals with hyperpronated and neutral foot type.  
conducted to identify any characteristics that might render participants ineligible for the study. The musculoskeletal assessment included evaluations of leg length [37], ankle dorsiflexion range of motion bilaterally with the weight-bearing lung test [38], and assessments for scoliosis [36].  
Volunteers who were deemed eligible for participation in the study were required to visit the facilities for a second session, during which they performed treadmill walking in random order at a 0% slope (level) at 5.0 km\(\cdot\)h\({}^{-1}\) (1.39 m\(\cdot\)s\({}^{-1}\)), uphill slopes of +10% and +20% at 3.5 km\(\cdot\)h\({}^{-1}\) (0.97 m\(\cdot\)s\({}^{-1}\)) and 2.5 km\(\cdot\)h\({}^{-1}\) (0.69 m\(\cdot\)s\({}^{-1}\)), respectively, and downhill slopes of \(-\)10% and \(-\)20% at 5.0 kg\(\cdot\)h\({}^{-1}\) (1.39 m\(\cdot\)s\({}^{-1}\)) and 3.5 kg\(\cdot\)h\({}^{-1}\) (0.97 m\(\cdot\)s\({}^{-1}\)), respectively. The variation in speeds between conditions reflected natural adaptations in walking speed to the slope of the terrain as determined by [PERSON] [39; 40]. Each walking condition lasted 5 min, with data collected during the final 4 min to allow participants accommodate to the respective conditions. Before testing, participants completed a 7 min familiarization session at a speed of 5.0 km\(\cdot\)h\({}^{-1}\) on a level treadmill surface to become familiar with the treadmill equipment [41]. A 5 min rest was allowed after the familiarization session, and 5 min breaks were provided between walking conditions to prevent fatigue. However, additional rest was given if a participant's heart rate, monitored using a Polar H10 heart rate monitor (Polar Electro, Kempele, Finland), exceeded 60% of their maximum heart rate (HRmax = [220 \(-\) age] \(\times\) 0.6) prior to the start of each walking condition. This threshold was consistent with the literature suggesting that such intensity levels are associated with high-demand activities and reduced postural control [42], which could potentially affect normal walking performance, particularly in conditions of extreme incline or decline on the treadmill. Participants were instructed to wear comfortable sportswear and walk unshod with fitted socks to reduce friction between the plantar surface and the treadmill belt. They were also advised to avoid strenuous physical activity prior to testing.