How perception of personal space influence obstacle avoidance during walking: differences between young and older...

Individuals maintain a spatial margin or 'personal space' between themselves and others. The form of this space and strategies for avoiding obstacles can be influenced by participant characteristics such as age. In this study, we investigated the characteristics of personal space and obstacle avoidance strategies in young and older adults. We also examined differences in perceptual personal space and walking trajectory during obstacle avoidance using a three-dimensional motion capture system. Methods Ten young adults and ten older adults participated in this study. We calculated actual obstacle avoidance trajectory and obstacle avoidance data such as the lateral spatial margin and body rotation angle during walking in a task that included obstacle avoidance. We also measured the perceptual personal space created by approaching a confederate. In order to calculate each personal space and obstacle avoidance data, we used a three-dimensional motion capture system. Two factors (two groups and personal space) of repeated analysis of variance were used in statistical analysis. Results We found no age-related differences in personal space or obstacle avoidance strategy in this study (F = 0.52, p = 0.48). However, we found significant differences in the form of perceptual personal space and personal space formed during obstacle avoidance (F = 11.86, p = 0.0030). Conclusion This study indicates that perceptual personal space did not reflect the walking trajectory created by actual obstacle avoidance. In addition, age did not influence the obstacle avoidance strategy. These results suggest that the perceptual personal space and aging have little effect in the situation of avoiding a single standing pedestrian.