Different types of mastoid vibration induce different responses to ground reaction force during walking: An exploratory study.

Background: Mastoid vibration (MV) helps detect changes in spatial-temporal gait parameters and margin of stability, allowing researchers to study how sensory input influences motor control strategies. Additionally, ground reaction force (GRF) measurement has widely emerged as a more accessible alternative to camera-based motion capture systems for detecting balance control in healthy and pathological groups in smaller clinical settings.

Research Question: Would different MV affect the GRF parameters in healthy young individuals?

Methods: Twenty young adults experienced MV unilaterally or bilaterally during walking to temporarily disrupt vestibular function. Dependent variables included amplitude of GRF peaks, time-to-peaks, and respective variabilities in anterior-posterior, medial-lateral, and vertical directions during weight acceptance (initial contact to loading response) and push-off (terminal stance) phases.

Results: A significant effect of MV was found in the amplitude of GRF peaks in the AP (F = 20.607, p < 0.001) and in the ML directions (F = 20.607, p < 0.001) during the weight acceptance period. In the AP direction, bilateral MV reduced amplitude of GRF peaks more than no MV (p < 0.001) and unilateral MV (p = 0.002). Unilateral MV increased ML GRF peak amplitude when compared with the application of no MV (p = 0.001) or bilateral MV (p = 0.024). MV didn't affect the time-to-peak of GRF between conditions.

Conclusion: These observations suggested that different types of MV induced different patterns of GRFs and respective variabilities. This foundational knowledge paves the way for developing new methods to identify and diagnose specific vestibular disorders.