Effects of Virtual Reality-Based Ladder Climbing on Distance Estimation, Fear, Muscle Activity: A Pilot Study

This pilot study investigated distance estimation, subjective fear, and lower-extremity muscle activity during physically embodied ladder climbing in immersive virtual reality (VR). Ten participants climbed an 8-foot ladder registered to a virtual ladder and were exposed to eight simulated elevations ranging from 0 to 100 m across two sessions. At each elevation, participants rated their fear, estimated distances to the ground and an overhead target, and completed a brief ascent and descent while muscle activity was recorded. Linear mixed-effects models showed that actual distance significantly predicted estimation error, with increasingly negative error as elevation increased, indicating greater underestimation at larger distances. Viewing direction had no significant effect. Fear increased significantly with virtual height and was lower during the second exposure session. Lower-extremity muscle activity did not differ significantly across height conditions. These findings show that ladder climbing in VR can elicit height-dependent changes in perceptual judgments and fear. The study demonstrates a method for increasing interaction fidelity in VR research on height perception and supports further investigation with larger samples and refined physiological measures.