## 4 Discussion  
This study examined the changes in loading rate and spatiotemporal, sagittal, and frontal joint kinematics and moment variables across arch-support orthosis conditions (2-mm, 6-mm, and 10-mm heel lift). In our study, wearing higher heel lift (e.g., D10) orthoses was shown to be associated with smaller loading rate, but larger rearfoot touchdown angle when compared to wearing lower heel lift orthoses (e.g., D2 and control). This is in line with previous studies, which suggested that wearing shoes with higher heel lift would lead to a smaller loading rate and larger foot strike angle [14; 25; 29; 32; 47; 50]. The decrease in loading rate would be resulted from lower peak pressure and contact area at rearfoot region in higher heel lift condition [51]. Previous studies have reported a decrease in loading rate when increasing the foot strike angle would be associated with the reduction of the risk potential of running-related injuries [28]. Our results found that orthoses with higher heel lift were associated with smaller maximum loading rate, which is not in line with another study which found higher loading rate in higher heel lift condition instead [47]. The contradicting findings for higher maximum loading rate could be due to the interaction of medial arch-support and fatigue. It is reported that fatigue alters running biomechanics and neuromuscular output in as little as 15 min of running [52]. Another study reported that the loading rate significantly increased following fatigue-inducing exercise of ankle dorsiflexors [53]. Since foot orthoses may reduce fatigue and overuse injuries through minimizing the localized plantar loading and altering the \"fit\" of the contour of the foot contact surface [5; 12; 6]. Future research should examine the efficiency of arch-support orthoses combined with varying heel lifts in reducing loading rate and altering sagittal joint kinematics when running during training and match. A higher heel lift is believed to increase the available range of motion of the rearfoot into dorsiflexion by placing the ankle in a more plantar flexed position [14]. Acute adaptations that may indicate a shift towards a more mid-foot running pattern have been reported to alter lower limb biomechanical characteristics included temporal-distances, plantar pressures, joint kinematics and loading, as well as muscle function [14; 15]. However, our study results indicated that some of the frontal forefoot and rearfoot angles (1.1 to 2.4 degree) were regarded as clinically insignificant (<2 degree), although they displayed statistically differences. Such small absolute amount of ankle angle changes was often found across various studies done on heel lift [19], heel curvature [54], and arch-support manipulation [55]. The results from this study could be clinically applicable for individuals with heel pain, Achilles tendon pain, and limited dorsiflexion RoM, who may benefit by wearing footwear/orthoses with a larger heel lift [16; 17; 20; 22; 24]. Additionally, we found an inverted U pattern for forefoot frontal RoM, with medium heel lift orthosis (D6) significantly differ from the D2 and D10. This partly supports the \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Orthosis Condition**} & \multicolumn{4}{c}{**ANOVA Results**} \\ \cline{2-7}  & **Flat** & **(Control)** & **D2** & **D6** & **D10** & **F-Value** & **\(p\)-Value** & **Partial Eta** \\  & **(**\(p_{p}\)**\({}^{2}\))** & & & & & **Squared (\(p_{p}\)\({}^{2}\))** \\ \hline \hline \end{tabular}  
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{7}{c}{BW = body weight; \({}^{\#}\) sig different from Control (\(p<0.05\)).} \\ \end{tabular}
\end{table} 
Table 4: Mean (SD) values and statistical results of joint moment variables by tested conditions. contention that an increase in the magnitude of heel lift does not necessarily result in a proportional change in joint kinematics [19]. Similarly, [PERSON] et al.