Step Into Tomorrow: Comparing Gait Patterns On A Vr Omni-directional Treadmill And Traditional Gait Modalities

Omnidirectional treadmills allow virtual reality (VR) users to move freely through a virtual environment. This recent technological advancement has paved the way for new opportunities for leveraging VR for novel rehabilitative paradigms. However, as frictionless omnidirectional treadmills require the user to slide their feet across a concave surface, it is possible that a walking pattern acquired on this treadmill is widely different from that of walking overground. Thus, examining the differences in gait patterns between omnidirectional treadmills and traditional modalities like conventional treadmills and overground walking is crucial. PURPOSE: To compare electromyographic (EMG) and spatiotemporal gait patterns in a healthy population while walking on a frictionless omnidirectional treadmill, a conventional treadmill, and overground walking. METHODS: Ten young, healthy participants were recruited to walk under three conditions: overground, conventional treadmill, and frictionless omnidirectional treadmill. Within these conditions, participants walked at preferred and fixed cadences (i.e., to the beat of a metronome) in both real-world and VR environments (12 conditions in total). Inertial measurement units and time-synchronized footswitches measured walking cadence and stride length. Root mean square (RMS) EMG data were used to determine relative medial gastrocnemius and biceps femoris activity under each of the 12 conditions. These data were normalized to the peak RMS value obtained during real-world preferred cadence overground walking. RESULTS: Preliminary results (n = 4) indicate medial gastrocnemius activity during stance phase greatly increased on the omnidirectional treadmill at a fixed cadence in both the real world (256% of overground walking) and in VR (142% of normal overground walking). Further, participants’ stride lengths drastically decreased across all omnidirectional treadmill conditions (mean = 0.55 m) compared to all overground walking conditions (mean = 1.05 m). In contrast, conventional treadmill EMG and spatiotemporal patterns were similar to those of overground walking. CONCLUSION: Walking on an omnidirectional treadmill greatly alters EMG and spatiotemporal gait patterns, calling into question its utility as a tool for VR-based gait rehabilitation.