Kenji Taneda1, Hiroki Mani2, Norio Kato3, Shunsuke Komizunai4, Keita Ishikawa5, Takashi Maruya6, Naoya Hasegawa7, Yasuyuki Takamatsu8, Tadayoshi Asaka9. 1. Graduate School of Health Sciences, Hokkaido University, Japan. Electronic address: tane.da34@gmail.com. 2. Faculty of Health Sciences, Hokkaido University, Japan. Electronic address: mani-hiroki@oita-u.ac.jp. 3. Faculty of Health Sciences, Hokkaido University of Science, Japan. Electronic address: kato-n@hus.ac.jp. 4. Graduate School of Information Science and Technology, Hokkaido University, Japan. Electronic address: komizunai@ssi.ist.hokudai.ac.jp. 5. Graduate School of Health Sciences, Hokkaido University, Japan. Electronic address: inikeita090807141@gmail.com. 6. Graduate School of Health Sciences, Hokkaido University, Japan. Electronic address: t-mry@yacht.ocn.ne.jp. 7. Faculty of Health Sciences, Hokkaido University, Japan. Electronic address: n_hasegawa@hs.hokudai.ac.jp. 8. Faculty of Health Sciences, Hokkaido University, Japan. Electronic address: takamatsu@hs.hokudai.ac.jp. 9. Faculty of Health Sciences, Hokkaido University, Japan. Electronic address: ask-chu@hs.hokudai.ac.jp.
Abstract
BACKGROUND: Integration of visual, vestibular, and proprioceptive sensations contributes to postural control. People with peripheral visual field loss have serious postural instability. However, the directional specificity of postural stability and sensory reweighting caused by gradual peripheral visual field loss remain unclear. RESEARCH QUESTION: What are the effects of peripheral visual field loss on static postural control? METHODS: Fifteen healthy young adults participated in this study. The participants were asked to stand quietly on a foam surface. Three conditions of virtual visual field loss (90°, 45°, and 15°) were provided by a head-mounted display, and ground reaction forces were collected using a force plate to calculate the displacements of the center of pressure (COP). RESULTS: The root mean square (RMS), mean velocity, and 95% ellipse area of COP displacements in the horizontal plane increased, and RMS in the anteroposterior (AP) direction was unchanged under the smallest visual field condition compared to the largest one. The power spectrum density of COP displacements in the low-frequency band was decreased and that in the medium-frequency band was increased in the AP direction. SIGNIFICANCE: During quiet standing of young healthy adults with peripheral visual field loss, increased peripheral visual field loss resulted in lower postural stability. Postural stability in the AP direction was maintained contrary to the functional sensitivity hypothesis. Peripheral visual field loss reduced the weighting of the visual input and increased that of the vestibular input in the AP direction to maintain equilibrium.
BACKGROUND: Integration of visual, vestibular, and proprioceptive sensations contributes to postural control. People with peripheral visual field loss have serious postural instability. However, the directional specificity of postural stability and sensory reweighting caused by gradual peripheral visual field loss remain unclear. RESEARCH QUESTION: What are the effects of peripheral visual field loss on static postural control? METHODS: Fifteen healthy young adults participated in this study. The participants were asked to stand quietly on a foam surface. Three conditions of virtual visual field loss (90°, 45°, and 15°) were provided by a head-mounted display, and ground reaction forces were collected using a force plate to calculate the displacements of the center of pressure (COP). RESULTS: The root mean square (RMS), mean velocity, and 95% ellipse area of COP displacements in the horizontal plane increased, and RMS in the anteroposterior (AP) direction was unchanged under the smallest visual field condition compared to the largest one. The power spectrum density of COP displacements in the low-frequency band was decreased and that in the medium-frequency band was increased in the AP direction. SIGNIFICANCE: During quiet standing of young healthy adults with peripheral visual field loss, increased peripheral visual field loss resulted in lower postural stability. Postural stability in the AP direction was maintained contrary to the functional sensitivity hypothesis. Peripheral visual field loss reduced the weighting of the visual input and increased that of the vestibular input in the AP direction to maintain equilibrium.
Authors: Brian Horsak; Mark Simonlehner; Lucas Schöffer; Bernhard Dumphart; Arian Jalaeefar; Matthias Husinsky Journal: Front Bioeng Biotechnol Date: 2021-12-03