## 4 Discussion  
To systematically investigate foot pathological conditions, objective biomechanical analyses of foot morphological characteristics and motion-sensitive information responses to different arch types are needed. The purpose of this study was to analyze differences in PGT and UGT with different arch stiffnesses while comparing biomechanical parameters. Consistent with our hypothesis, different arch stiffnesses showed significant differences in ROMs on multiple planes of lower limb joints during PGT and UGT. Moreover, the plantar pressure data, represented by the maximum pressure, also showed significant differences in the forefoot and rearfoot areas. Gait termination patterns have a certain impact on joint ROMs. Compared with PGT, subjects showed a significantly larger ROM in the hip joint in the sagittal plane and knee joint in the transverse plane during UGT. Combined with related kinetic data [8; 22], [PERSON] et al. [23] demonstrated that UGT with self-selected walking speed and PGT with fast walking speed have similar biomechanical characteristics. This may be a reaction that allows the body to absorb the sudden increases in ground reaction forces and control the movement of the center of mass [23]. However, relative to PGT, significant decreases in hip ROM existed in UGT because of the decrease in maximum abduction angles. According to the results of a previous study [23], when the subjects performed gait termination without unexpected stimulus, they showed gait characteristic differences on spatiotemporal parameters such as slower velocity normalized by the Froude number and longer stop step length. In a relatively short termination time, the hip joints may not be able to show a larger magnitude of movement in the frontal plane due to anatomical structure [24]. Previous studies [23; 25; 26] stressed that the knee and hip joint angles are the prime variables of interest for stopping tasks. In the current study, however, subjects showed a greater ROM in the sagittal as well as frontal planes of the ankle joint during UGT, which is related to the larger plantarflexion angles and peak eversion during the process. Considering previously explored foot balance differences between two types of gait termination, this may result in gait imbalance and an increased risk of joint damage [27]. As a multi-segmental system, the movements of the hip, knee, and ankle joints are linked with the lower extremity kinetic chain [28]. However, the difference in the  
Figure 3: The plantar pressure during planned and unplanned gait termination in stiff arches and flexible arches. Notes: * means the main effect of terminalation pattern; # means the main effect of arch stiffness; & means interaction. morphology of the arch has no significant effect on kinematic compensation of the relative proximal joints such as the hip and knee joints. The more flexible arch means that the foot can withstand a wider range of motion during gait (the propensity for FA to splay under loads) [14]. Kinematic results from the current study demonstrated that the MTP joints of subjects with FA showed a greater ROM in the sagittal plane during the termination of gait, although this was not significant (\(p>0.05\)). In contrast, in the frontal plane, FA showed a significant increase in ROM, which may be a response to the comprehensive integration of the compensatory adjustment to compensate for the increase in the plantar flexion of the MTP joints and stabilize the joint [28]. [PERSON] et al. [13] found that there was a weak significant correlation between the arch height and arch stiffness, with a flatter arch corresponding to a more flexible arch. At the same time, previous research [5] reported that, compared to the planus foot, the cavus foot had increased valgus and adduction in the forefoot. During the terminal stance, plantar aponeurosis is less able to be tensioned with MTP extension.