Role of vestibular sensor on body sway control: Coherence between head acceleration and stabilogram

This work aims at evaluating the role of the vestibular system in the postural sway control using the coherence function. A sample of 19 young, healthy male adults was monitored with a three axial accelerometer placed over the head during a stabilometric test, standing on a force platform during 3 min in four conditions: eyes closed and open, and feet apart and together. The magnitude squared coherence (MSC) function and Monte Carlo simulation was used to correlate changes in body sway with head accelerations. Significant MSC values were found in the frequency range 0.1-0.5 Hz, mainly in conditions of larger oscillations: eyes closed and feet together. These results may be related to utricular otoliths responses and ankle strategy.