Kinematic Gait Adjustments to Virtual Environments on Different Surface Conditions: Do Treadmill and Over-Ground Walking Exhibit Different Adaptations to Passive Virtual Immersion?

Abstract

Background. The aim of this study was to examine the kinematic gait adjustments performed in response to passive and photorealistic virtual reality environment (VRE) demands during over-ground and treadmill walking conditions and determine whether the surface presentation order affects the gait adjustments in response to different VREs. Methods. Twenty young participants divided into two groups performed two virtual reality (VR) walking protocols which included two different VREs (snowy and crowded conditions). Group A performed the VR over-ground protocol (four natural walking (NW), seven VR snowy, and seven VR crowded trials) followed by the VR treadmill protocol (four NW, one VR snowy, and one VR crowded trials); Group B performed the VR treadmill protocol (four NW, seven VR snowy, and seven VR crowded trials) followed by the VR over-ground protocol (four NW, one VR snowy, and one VR crowded trials). Center of mass (COM) excursion angles and mediolateral (ML) COM excursions were analyzed and used as outcome measures. Results. Group A showed higher COM excursion angles and ML-COM excursion on over-ground VR trials compared to NW trials ( p < 0.05 ), while Group B only showed kinematic changes for the crowded VRE compared to NW trials during the treadmill walking protocol ( p < 0.05 ). Post over-ground exposure, Group A showed greater COM excursion angle and ML-COM excursions on VR trials compared to NW trials during the treadmill walking protocol ( p < 0.05 ). Post treadmill exposure, Group B only showed higher COM excursion angles for the snowy VRE compared to NW trials during the over-ground walking protocol ( p < 0.01 ). Conclusion. Results showed that higher kinematic gait adjustments in response to VRE demands were observed during over-ground walking. Additionally, higher sensorimotor responses to VRE demands were observed when the VR protocol was first performed on the over-ground surface and followed by the treadmill walking condition (Group A) compared to the opposite (Group B).

Virtual reality assessment of walking in a modifiable urban environment: a feasibility and acceptability study

“…1 ). As noted, overground walking induces larger mechanical walking adjustments when required by the environment presented in VR than treadmills, meaning individuals kinematically respond more to environmental cues 88 . Due to these differences between treadmill walking and overground walking, for testing the effects of environmental changes on overground walking, it would be preferable to test these effects on overground walking, rather than walking on treadmills.…”

“…The HP Z VR Backpack G1 Workstation computer with Intel ® Core™ i7-7820HQ running Windows 10 Version 1809 was paired with the Samsung HMD Odyssey Windows Mixed Reality Headset (Model XE800ZAA-HC1US) with Motion Controllers (Models AA-HCIHULB & AA-HCIHURB). Using a backpack computer provided participants the ability to walk freely overground; as discussed, overground walking evokes greater mechanical responses to environments 88 . We chose the Samsung HMD Odyssey because its display is of a high resolution, and it is capable of eye-tracking data (not used for the present study).…”

“…There is a limited volume of recently published studies describing the relationship between walking kinematics in the real-world and overground walking, and we have seen mixed results here. Individuals adjust their walking mechanics to respond to VR environmental demands while on a treadmill 87 but adjust more so more during overground walking 88 . Some studies showed that there is no significant difference between walking in a virtual environment and in a real-world situation, and people are able to adapt to the virtual environment 72,89 .…”

Overground Walking in a Fully Immersive Virtual Reality: A Comprehensive Study on the Effects on Full-Body Walking Biomechanics

“…Otherwise, it will not be possible to put VR overground scenarios as a purposeful utility into both clinical and research practice for gait rehabilitation. While there are a few studies available describing the effect of walking in a VR on the treadmill ( van der Krogt et al, 2014 ; Chan et al, 2019 ; Varas-Diaz et al, 2020 ), there is only very limited and partly contradictory research available which specifically addressed VR overground walking. For example, existing studies only partly reported adaptions to walking speed, cadence, step width, and step length next to increased variability of the same parameters ( Janeh et al, 2018 ; Canessa et al, 2019 ; Martelli et al, 2019 ).…”

“…For example, existing studies only partly reported adaptions to walking speed, cadence, step width, and step length next to increased variability of the same parameters ( Janeh et al, 2018 ; Canessa et al, 2019 ; Martelli et al, 2019 ). One study reported kinematic gait adjustments in terms of increased center of mass excursion ( Varas-Diaz et al, 2020 ). Besides the contradictory nature of the existing literature, it is limited to simple analysis of spatio-temporal gait parameters or center of mass excursion.…”