仮想高さ暴露中の動的バランスパフォーマンスにおける年齢と腕の動きの条件の影響

Dynamic balance performance during natural height exposure is affected by age and arm movement condition. However, it remains unclear whether these effects persist during virtual height exposure. The objective of the present study is to investigate the effects of age and arm movement condition during virtual height exposure.

A sample of 39 children (11.0 ± 0.5 years), 40 adolescents (14.4 ± 0.6 years), and 43 young adults (23.6 ± 3.6 years) performed two balancing trials (one with free and one with restricted arm movements) in a randomized order during virtual height exposure. The time taken to complete the forward and backward traversal of the beam was recorded for analysis. In addition, perceptual outcomes (i.e., instability, task difficulty, fear of falling, and conscious balance processing), presence, and virtual reality (VR) sickness were assessed after each trial.

There were no significant (all p > 0.05) effects of arm condition and no arm-by-age group interaction effects. Significant age group effects were observed for the total (p < 0.01, Cohen's d = 0.48) and the backward balancing time (p < 0.01, Cohen's d = 0.57), with children performing significantly longer than adolescents. Young adults reported significantly greater task difficulty (p < 0.01, Cohen's d = 0.59) and stronger involvement (p < 0.01, Cohen's d = 0.72) compared with adolescents. All variables were also analyzed according to trial number (i.e., first vs. second), revealing that-irrespective of arm condition-all measures significantly (all p < 0.05) improved from the first to the second trial. Significant trial-by-age group interactions (all p < 0.05, η _p ² = 0.06-0.11) indicated that compared to adolescents and young adults, children took longer to cross the beam during the first trial.

The present findings suggest that participants quickly habituated to the VR environment, which may have masked potential benefits of free arm movement during dynamic balancing. In contrast, the observed age-related effects differ from those reported in from studies using actual height elevations, highlighting the need for further research on the effects of VR on balance performance and perceptual outcomes.