Difference between visual feedback and visual suppression upon the stabilization of body sway in normal subjects

Area of Science:

• Biomechanics
• Human sensorimotor control
• Vision science

Background:

• Maintaining balance is crucial for daily activities and preventing falls.
• Body sway, the uncontrolled side-to-side movement of the body, is a key indicator of balance.
• Visual information plays a significant role in postural control.

Purpose of the Study:

• To investigate the effect of visual feedback on body sway stabilization.
• To determine how real-time visual display of foot pressure influences postural control.
• To analyze the frequency characteristics of body sway under visual feedback conditions.

Main Methods:

• Developed a microcomputer system for real-time visual feedback of the center of foot pressure (CoP).
• Subjects were instructed to align their CoP with target lines on a computer display.
• Analyzed the power spectra of body sway, focusing on the lateral (Y) component.

Main Results:

• Visual feedback significantly shifted the peak frequency of body sway towards higher ranges in the lateral direction.
• This frequency shift indicates a change in the control strategy for body sway.
• The system effectively provided real-time data on foot pressure for balance adjustment.

Conclusions:

• Visual feedback of body sway, particularly in the lateral direction, enhances postural stability.
• The system relies on visual error signals, comparing foveal vision to the image, to stabilize body sway.
• This study highlights the importance of visual input for fine-tuning balance control mechanisms.