## 4 Discussion
### Synchronized Walking Avaatar and Audio Cues on Gait Guidance  
The system developed in this study demonstrated the potential to effectively guide the participants' gait by using a combination of a synchronized walking avatar and auditory cues. The avatar, which was modeled after healthy gait patterns, provided a consistent and natural visual reference for the participants. This visual cue may have activated the mirror neuron system, a neural mechanism that allows individuals to learn and refine motor skills through observation and imitation [43; 44]. By observing the avatar's movements from behind, participants were likely able to internalize and mimic the gait pattern, thereby improving their own walking technique [45]. This is in contrast with the study by [PERSON] et al., which did not show significant changes in step length when viewing the avatar from behind [21]. Once participants started walking with the avatar as a dyad, the changes in distance between the two prompted a change in their stride length [46]. Despite not being instructed to maintain the distance, the participants likely modified their stride lengths to keep a constant distance from the avatar [47]. The visual cues in the form of the avatar and the activation of the mirror neuron system also showed significant effects on the speed of the participants. Other studies using rhythmical visual stimuli, such as [PERSON] et al. 's, revealed stride length guidance but no significant changes in speed as found in this study [48]. Similarly, other studies using rhythmical visual stimuli found significant effects on stride length but no significant changes in gait speed as found in this study [49]. These effects could be attributed to reduced attentional demand with subconscious reactions through the mirror neuron system when using the avatar compared with the increased attentional demand found with other visual cues [50; 51]. Although the use of avatars can reduce attentional demand, other studies using avatars, such as [PERSON] et al. 's, found increased cognitive demand limiting the effects when participants tried to synchronize their steps to the avatar's [52]. In this study, by using the avatar synchronized to the user, we reduced the cognitive load for the user. [PERSON] et al. suggested that if the avatar's movements do not closely match the user's pace or rhythm, it may disrupt the user's natural gait cycle and lead to increased variability and reduced effects [53]. The synchronization system developed in this study for elderly gait showed significant effects on the gait parameters. The system showed similar significant effects on the elderly as our previous study on healthy young participants [25]. This is in contrast with previous studies' expectations that age would affect the outcome of the avatar-based method [54]. The synchronized auditory cues acted as rhythmic signals that complemented the visual feedback from the avatar, making it easier for participants to maintain a consistent pace and rhythm. Interactive and mutual synchronization between the avatar's and participant's rhythms allowed for temporal guidance of the participant's gait [55]. The effectiveness of this interactive synchronization supports previous research studies, such as [PERSON] et al. (2012) and [PERSON] (2009), both of which showed temporal gait guidance through interpersonal mutual synchronization between system and user [55; 56]. The effectiveness of rhythmic cues can decrease if they are not properly aligned with the individual's natural pace or if they become too cognitively demanding [57]. The mutual synchronization of the system and participant reduced the increased attentional demand, gait variability, and reduced stability shown in previous studies [58; 59]. Overall, the participants verbally reported that the synchronized visual and auditory feedback made it easier to adjust their gait, particularly in maintaining a steady tempo and achieving a balanced stride.