Balance control mechanisms do not benefit from successive stimulation of different sensory systems

PLoS One. 2019 Dec 11;14(12):e0226216. doi: 10.1371/journal.pone.0226216. eCollection 2019.

Abstract

In humans, to reduce deviations from a perfect upright position, information from various sensory cues is combined and continuously weighted based on its reliability. Combining noisy sensory information to produce a coherent and accurate estimate of body sway is a central problem in human balance control. In this study, we first compared the ability of the sensorimotor control mechanisms to deal with altered ankle proprioception or vestibular information (i.e., the single sensory condition). Then, we evaluated whether successive stimulation of difference sensory systems (e.g., Achilles tendon vibration followed by electrical vestibular stimulation, or vice versa) produced a greater alteration of balance control (i.e., the mix sensory condition). Electrical vestibular stimulation (head turned ~90°) and Achilles tendon vibration induced backward body sways. We calculated the root mean square value of the scalar distance between the center of pressure and the center of gravity as well as the time needed to regain balance (i.e., stabilization time). Furthermore, the peak ground reaction force along the anteroposterior axis, immediately following stimulation offset, was determined to compare the balance destabilization across the different conditions. In single conditions, during vestibular or Achilles tendon vibration, no difference in balance control was observed. When sensory information returned to normal, balance control was worse following Achilles tendon vibration. Compared to that of the single sensory condition, successive stimulation of different sensory systems (i.e., mix conditions) increased stabilization time. Overall, the present results reveal that single and successive sensory stimulation challenges the sensorimotor control mechanisms differently.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Achilles Tendon / physiology*
  • Adult
  • Ankle / physiology
  • Electric Stimulation
  • Female
  • Humans
  • Male
  • Postural Balance*
  • Proprioception
  • Vestibule, Labyrinth / physiology*
  • Vibration
  • Young Adult

Grants and funding

This research was supported by grant from the Natural Sciences and Engineering Research Council of Canada Discovery program (RGPIN-2015-04068) to MS. JPC was supported by scholarships from Fonds de Recherche du Québec en Santé (FRQ-S) and the Wilbrod-Bhérer recruitment scholarship. NA received a summer research scholarship from Laval University, Faculty of Medicine. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.