Using Low Levels of Stochastic Vestibular Stimulation to Improve Balance Function

Area of Science:

• Neuroscience
• Biomechanics
• Rehabilitation Engineering

Background:

• Low-level stochastic vestibular stimulation (SVS) has shown promise for improving medio-lateral (ML) postural responses.
• The effects of SVS on anterior-posterior (AP) balance and cross-planar balance control remain largely uninvestigated.

Purpose of the Study:

• To investigate the efficacy of low-amplitude SVS in the 0-30 Hz range applied in the ML direction for enhancing cross-planar balance function.
• To determine the optimal stimulus amplitude for improving balance across ML, AP, and combined APML directions.

Main Methods:

• Forty-five participants stood on a compliant surface with eyes closed, receiving binaural bipolar SVS in the ML direction.
• Quantified head, trunk, and whole-body stability in ML, AP, and APML directions.
• Measured perceptual and body motion thresholds to estimate internal noise during seated sinusoidal stimulation.

Main Results:

• Binaural bipolar SVS in the ML direction significantly improved balance performance in all three directions (ML, AP, APML).
• Optimal stimulus amplitudes for balance improvement were predominantly in the 100-500 μA range, demonstrating stochastic resonance (SR).
• Average optimal SVS amplitude, normalized to perceptual threshold, was 46% (ML), 53% (AP), and 50% (APML).

Conclusions:

• Low-level stochastic vestibular stimulation applied in the ML direction effectively enhances balance control in ML, AP, and combined directions.
• The findings suggest a potential therapeutic application for SVS devices in improving balance for individuals with age-related decline, Parkinson's disease, or following spaceflight.