A comparison of balance between real and virtual environments: differences, role of visual cues and full-body avatars, a quasi-experimental clinical study

Virtual rehabilitation using Virtual Reality (VR) technology is a promising novel approach to rehabilitation. However, postural responses in VR differ significantly from real life. The introduction of an avatar or visual cues in VR could help rectify this difference. An initial session was used to assess static and dynamic balance performances between VR and real life to set the reference values. A second session involved three VR conditions applied in a randomised order: i.e. full-body avatar, enhanced visual cues, or a combination of both conditions. Performances of the centre of pressure (COP) were recorded on a force plate. Seventy (70) people took part in the first session and 74 in the second. During the first session, a significant difference was observed in left static, right static and right dynamic COP distance (respectively SMD = − 0.40 [− 0.73, − 0.06], p = 0.02, − 0.33 [− 0.67, 0.00], p = 0.05, SMD = − 0.61 [− 0.95, − 0.27], p < 0.001) and a non-significant difference in the left dynamic, SMD = − 0.22 [− 0.56, 0.11], p = 0.19). During the second session it was observed that this difference was corrected mainly by reinforced visual information and to a lesser extent by the presence of a full-body avatar. Balance disruption triggered by the use of virtual reality can be offset by vertical visual information and/or by the presence of a full-body avatar. Further research is required on the effects of a full-body avatar.