Effects of Self-Projection through Mixed Reality on Walking Posture in Environment with Constrained Limb Movement

The posture of a person changes due to various factors, causing accidents or illnesses. We examined walking posture using the self-projection method (SPM) in mixed-reality environments where upper- and lower-limb movements were constrained to simulate tasks such as obstacle avoidance and carrying objects. The SPM uses mixed-reality goggles to display a three-dimensional avatar representing the user's walking posture in real time, allowing users to visually monitor and adjust their gait through feedback-driven implicit learning. We selected 10 healthy men and compared their walking postures in two scenarios: walking freely while avoiding obstacles (SO task) and walking while also carrying a cup on a tray (SC task). The postural changes resulting from the support provided by the SPM were analyzed. The results indicated that the support reduced forward trunk tilt and its longitudinal and lateral movements during walking. A strong corrective effect was observed in lateral sway during the SO task. Moreover, the SPM reduced longitudinal swaying of the trunk and significantly decreased forward tilt in the SC task. These results indicate that the SPM, which relies on implicit learning, is effective in stabilizing walking posture and reducing the risk of falls in environments with constrained limb movements.