Gait Speed Modulations Are Proportional to Grades of Virtual Visual Slopes—A Virtual Reality Study
Gait is a complex mechanism relying on integration of several sensory inputs such as vestibular, proprioceptive, and visual cues to maintain stability while walking. Often humans adapt their gait to changes in surface inclinations, and this is typically achieved by modulating walking speed according...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2021-08-01
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| Series: | Frontiers in Neurology |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fneur.2021.615242/full |
| _version_ | 1819068734941167616 |
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| author | Amit Benady Amit Benady Amit Benady Sean Zadik Gabriel Zeilig Gabriel Zeilig Gabriel Zeilig Sharon Gilaie-Dotan Sharon Gilaie-Dotan Sharon Gilaie-Dotan Meir Plotnik Meir Plotnik Meir Plotnik |
| author_facet | Amit Benady Amit Benady Amit Benady Sean Zadik Gabriel Zeilig Gabriel Zeilig Gabriel Zeilig Sharon Gilaie-Dotan Sharon Gilaie-Dotan Sharon Gilaie-Dotan Meir Plotnik Meir Plotnik Meir Plotnik |
| author_sort | Amit Benady |
| collection | DOAJ |
| description | Gait is a complex mechanism relying on integration of several sensory inputs such as vestibular, proprioceptive, and visual cues to maintain stability while walking. Often humans adapt their gait to changes in surface inclinations, and this is typically achieved by modulating walking speed according to the inclination in order to counteract the gravitational forces, either uphill (exertion effect) or downhill (braking effect). The contribution of vision to these speed modulations is not fully understood. Here we assessed gait speed effects by parametrically manipulating the discrepancy between virtual visual inclination and the actual surface inclination (aka visual incongruence). Fifteen healthy participants walked in a large-scale virtual reality (VR) system on a self-paced treadmill synchronized with projected visual scenes. During walking they were randomly exposed to varying degrees of physical-visual incongruence inclinations (e.g., treadmill leveled & visual scene uphill) in a wide range of inclinations (−15° to +15°). We observed an approximately linear relation between the relative change in gait speed and the anticipated gravitational forces associated with the virtual inclinations. Mean relative gait speed increase of ~7%, ~11%, and ~17% were measured for virtual inclinations of +5°, +10°, and +15°, respectively (anticipated decelerating forces were proportional to sin[5°], sin[10°], sin[15°]). The same pattern was seen for downhill virtual inclinations with relative gait speed modulations of ~-10%, ~-16%, and ~-24% for inclinations of −5°, −10°, and −15°, respectively (in anticipation of accelerating forces). Furthermore, we observed that the magnitude of speed modulation following virtual inclination at ±10° was associated with subjective visual verticality misperception. In conclusion, visual cues modulate gait speed when surface inclinations change proportional to the anticipated effect of the gravitational force associated the inclinations. Our results emphasize the contribution of vision to locomotion in a dynamic environment and may enhance personalized rehabilitation strategies for gait speed modulations in neurological patients with gait impairments. |
| first_indexed | 2024-12-21T16:38:52Z |
| format | Article |
| id | doaj.art-54d2f28f86584aa38e8b941fe6fd68b0 |
| institution | Directory Open Access Journal |
| issn | 1664-2295 |
| language | English |
| last_indexed | 2024-12-21T16:38:52Z |
| publishDate | 2021-08-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Neurology |
| spelling | doaj.art-54d2f28f86584aa38e8b941fe6fd68b02022-12-21T18:57:09ZengFrontiers Media S.A.Frontiers in Neurology1664-22952021-08-011210.3389/fneur.2021.615242615242Gait Speed Modulations Are Proportional to Grades of Virtual Visual Slopes—A Virtual Reality StudyAmit Benady0Amit Benady1Amit Benady2Sean Zadik3Gabriel Zeilig4Gabriel Zeilig5Gabriel Zeilig6Sharon Gilaie-Dotan7Sharon Gilaie-Dotan8Sharon Gilaie-Dotan9Meir Plotnik10Meir Plotnik11Meir Plotnik12Center of Advanced Technologies in Rehabilitation, Sheba Medical Center, Ramat Gan, IsraelSchool of Optometry and Vision Science, Bar Ilan University, Ramat Gan, IsraelThe Gonda Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, IsraelCenter of Advanced Technologies in Rehabilitation, Sheba Medical Center, Ramat Gan, IsraelDepartment of Neurological Rehabilitation, Sheba Medical Center, Ramat Gan, IsraelDepartment of Physical and Rehabilitation Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, IsraelSchool of Health Professions, Ono Academic College, Kiryat Ono, IsraelSchool of Optometry and Vision Science, Bar Ilan University, Ramat Gan, IsraelThe Gonda Multidisciplinary Brain Research Center, Bar Ilan University, Ramat Gan, IsraelUCL Institute of Cognitive Neuroscience, London, United KingdomCenter of Advanced Technologies in Rehabilitation, Sheba Medical Center, Ramat Gan, IsraelDepartment of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, IsraelThe Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, IsraelGait is a complex mechanism relying on integration of several sensory inputs such as vestibular, proprioceptive, and visual cues to maintain stability while walking. Often humans adapt their gait to changes in surface inclinations, and this is typically achieved by modulating walking speed according to the inclination in order to counteract the gravitational forces, either uphill (exertion effect) or downhill (braking effect). The contribution of vision to these speed modulations is not fully understood. Here we assessed gait speed effects by parametrically manipulating the discrepancy between virtual visual inclination and the actual surface inclination (aka visual incongruence). Fifteen healthy participants walked in a large-scale virtual reality (VR) system on a self-paced treadmill synchronized with projected visual scenes. During walking they were randomly exposed to varying degrees of physical-visual incongruence inclinations (e.g., treadmill leveled & visual scene uphill) in a wide range of inclinations (−15° to +15°). We observed an approximately linear relation between the relative change in gait speed and the anticipated gravitational forces associated with the virtual inclinations. Mean relative gait speed increase of ~7%, ~11%, and ~17% were measured for virtual inclinations of +5°, +10°, and +15°, respectively (anticipated decelerating forces were proportional to sin[5°], sin[10°], sin[15°]). The same pattern was seen for downhill virtual inclinations with relative gait speed modulations of ~-10%, ~-16%, and ~-24% for inclinations of −5°, −10°, and −15°, respectively (in anticipation of accelerating forces). Furthermore, we observed that the magnitude of speed modulation following virtual inclination at ±10° was associated with subjective visual verticality misperception. In conclusion, visual cues modulate gait speed when surface inclinations change proportional to the anticipated effect of the gravitational force associated the inclinations. Our results emphasize the contribution of vision to locomotion in a dynamic environment and may enhance personalized rehabilitation strategies for gait speed modulations in neurological patients with gait impairments.https://www.frontiersin.org/articles/10.3389/fneur.2021.615242/fullvirtual realitygait speedvisual-physical conflict processingrod and framesubjective visual verticaluphill and downhill locomotion |
| spellingShingle | Amit Benady Amit Benady Amit Benady Sean Zadik Gabriel Zeilig Gabriel Zeilig Gabriel Zeilig Sharon Gilaie-Dotan Sharon Gilaie-Dotan Sharon Gilaie-Dotan Meir Plotnik Meir Plotnik Meir Plotnik Gait Speed Modulations Are Proportional to Grades of Virtual Visual Slopes—A Virtual Reality Study Frontiers in Neurology virtual reality gait speed visual-physical conflict processing rod and frame subjective visual vertical uphill and downhill locomotion |
| title | Gait Speed Modulations Are Proportional to Grades of Virtual Visual Slopes—A Virtual Reality Study |
| title_full | Gait Speed Modulations Are Proportional to Grades of Virtual Visual Slopes—A Virtual Reality Study |
| title_fullStr | Gait Speed Modulations Are Proportional to Grades of Virtual Visual Slopes—A Virtual Reality Study |
| title_full_unstemmed | Gait Speed Modulations Are Proportional to Grades of Virtual Visual Slopes—A Virtual Reality Study |
| title_short | Gait Speed Modulations Are Proportional to Grades of Virtual Visual Slopes—A Virtual Reality Study |
| title_sort | gait speed modulations are proportional to grades of virtual visual slopes a virtual reality study |
| topic | virtual reality gait speed visual-physical conflict processing rod and frame subjective visual vertical uphill and downhill locomotion |
| url | https://www.frontiersin.org/articles/10.3389/fneur.2021.615242/full |
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