Subthreshold stochastic vestibular stimulation affects balance-challenged standing and walking

Area of Science:

• Neuroscience
• Biomechanics
• Human Motor Control

Background:

• Subthreshold stochastic vestibular stimulation (SVS) is theorized to enhance vestibular sensitivity and improve balance.
• Limited understanding exists regarding SVS effects on standing and walking under challenged balance conditions, particularly with open eyes.
• The influence of different intensity determination methods on SVS efficacy remains unclear.

Purpose of the Study:

• To investigate the effect of SVS on stability during eyes-open standing and overground walking with challenged balance.
• To compare the impact of SVS intensity determined by sinusoidal versus cutaneous threshold techniques.

Main Methods:

• Thirteen healthy adults participated in standing and walking tasks under both balance-challenged and un-challenged conditions.
• Balance challenge was induced using inflatable hemispheres attached to footwear, limiting base of support control.
• Subthreshold stochastic vestibular stimulation (SVS) or sham stimulation was applied, with intensity set at 50% of sinusoidal or 80% of cutaneous threshold.

Main Results:

• SVS significantly reduced medial-lateral trunk velocity root mean square during balance-challenged standing (p < 0.05).
• During eyes-open walking, SVS decreased step-width variability and marginally increased gait speed (p < 0.05) irrespective of balance condition.
• The method used to determine SVS intensity showed minimal impact on the observed standing and walking outcomes.

Conclusions:

• Subthreshold stochastic vestibular stimulation (SVS) enhances balance control during challenging standing and walking tasks in healthy adults.
• SVS demonstrates effectiveness in improving gait parameters and trunk stability, particularly under eyes-open conditions.
• The findings suggest SVS is a promising non-invasive method for augmenting vestibular function and improving postural control.