## 4 Discussion
Although, overall, fallers had more knee flexion in all gait cycle and less ankle plantar flexion than non-fallers during forward progression, this result suggests that fallers used more knee extension but less ankle plantar flexion for forward progression. Moreover, fallers showed less anti-phase coordination patterns in knee flexion-ankle plantar flexion with knee dominancy (315-360\({}^{\circ}\)) than non-fallers, which is related to the loading response and late swing. Fallers may have more knee flexion and more ankle plantar flexion during the late swing phase and initial contact, resulting in sooner foot contact with the ground and shorter contralateral single-limb support time. This pattern may help fallers in keeping their center of mass low and in walking with more caution. Moreover, as fallers have more plantar flexion during the late swing phase, they might use more knee flexion during the swing phase to increase foot clearance. Our results showed that the CoordV in the ankle-to-knee pattern was significantly lower in fallers than in non-fallers in the late swing phase (Figure 4b), which is in agreement with the results of [PERSON] et al., who reported a lower variability of knee-ankle inter-joint coordination during the swing phase in older adults [28]. In our study, vector coding was used to quantify the coordination, and all phases of the gait cycle were analyzed. This lower CoordV in fallers could indicate an inconsistency in neuromuscular control and reduced ability to control the motion of the leg in preparation for foot contact. Overall, the results for the ankle-to-knee coordination pattern indicate that fallers walk with more ankle dorsiflexion and less plantar flexion pattern during forward progression than non-fallers, and that the knee of fallers is in greater flexion than that of non-fallers in all gait cycles. However, the less plantarflexion indicates that fallers cannot generate enough power to walk at the same cadence and gait speed as non-fallers. Our results showed that fallers had a less anti-phase coordination pattern in hip extension-knee flexion with hip dominancy (135-180\({}^{\circ}\)) compared to non-fallers (Figure 2), which occurred in the loading response and push-off phases. Fallers showed more knee flexion and less hip extension in the loading response and push-off phase than non-fallers (Figure 2). Moreover, fallers also had more ankle plantar flexion during the loading response phase than non-fallers (Figure 1). These patterns of joint motion in fallers may be a strategy to land the leg on the ground with more ankle plantar flexion, knee flexion, and less hip extension to control the foot contact with the ground and the loading response. More ankle plantar flexion and less hip extension with more knee flexion cause less power generation during the push-off phase in fallers, which may indicate going to the single-leg support phase with caution. This result is in line with the results of the study by [PERSON], which showed smaller ankle plantarflexion and hip extension during push-off in fallers than in non-fallers [41]. Our results showed that fallers exhibit smaller CoordV in the knee-to-hip coordination during loading response than non-fallers (Figure 4c), which may indicate a reduction in degree of freedom in this phase. They may try to reduce their knee-to-hip CoordV due to more cautious loading response compared to non-fallers, at the expense of less ability to adapt to disturbances. The results also showed that fallers had a more in-phase coordination pattern in hip flexion-ankle dorsiflexion with hip dominancy (0-45\({}^{\circ}\)) compared to non-fallers (Figure 3), which occurred in the initial and mid swing phases. This pattern indicates that fallers have more hip flexion and ankle dorsiflexion during the initial and mid swing phases, which may cause lower foot clearance and increased risk of falling.