[Purpose] Falls can significantly affect elderly individuals. However, most current
methods used to detect and analyze high-risk conditions make use of simulated falling
movements for data collection, which may not accurately represent actual falls. The
present study aimed to induce natural falls using visual and auditory stimuli to create
unstable walking conditions. [Participants and Methods] Two experiments were performed.
The first experiment focused on inducing unstable walking using visual stimuli; whereas,
the second experiment combined visual and auditory stimuli. To investigate the effects of
stimuli on the induction of unstable walking, our results were compared with those of
normal walking conditions. In addition, the two experimental conditions were compared to
identify the most effective stimuli. [Results] Both experiments revealed a decrease in
step length, an increase in step time and width, and an increase in the coefficient of
variation of measurements, indicating an induced walking pattern with a higher risk of
falls. Furthermore, combining visual and auditory stimuli caused deterioration of
inter-limb coordination, as observed through an increased phase coordination index, thus
resulting in further instability during walking. [Conclusion] Visual and auditory stimuli
induced unstable walking. In particular, the combination of visual and auditory stimuli
with a 0.8-s rhythm increased instability.