The Influence of Visual Perception of Self-Motion on Locomotor Adaptation to Unilateral Limb Loading

ABSTRACT

Self-perception of motion through visual stimulation may be important for adapting to locomotor conditions. Unilateral limb loading is a locomotor condition that can improve stability and reduce abnormal limb movement. In the present study, the authors investigated the effect of self-perception of motion through virtual reality (VR) on adaptation to unilateral limb loading. Healthy young adults, assigned to either a VR or a non-VR group, walked on a treadmill in the following 3 locomotor task periods—no load, loaded, and load removed. Subjects in the VR group viewed a virtual corridor during treadmill walking. Exposure to VR reduced cadence and muscle activity. During the loaded period, the swing time of the unloaded limb showed a larger increase in the VR group. When the load was removed, the swing time of the previously loaded limb and the stance time of the previously unloaded limb showed larger decrease and the swing time of the previously unloaded limb showed a smaller increase in the VR group. Lack of visual cues may cause the adoption of cautious strategies (higher muscle activity, shorter and more frequent steps, changes in the swing and stance times) when faced with situations that require adaptations. VR technology, providing such perceptual cues, has an important role in enhancing locomotor adaptation.

Keywords:

• ankle weight
• gait
• motor learning
• virtual reality
• vision

ACKNOWLEDGMENTS

This research was funded by grants awarded to Nicholas Stergiou by the Nebraska Research Initiative and the NIH (K25HD047194), to Dimitrios Katsavelis by the University of Nebraska Medical Center (doctoral fellowship), and to Mukul Mukherjee by the American Heart Association (#0820136Z).

Notes

The optic flow referred here is the forward optic flow.