Human body-sway steady-state responses to small amplitude tilts and translations of the support surface -- Effects of superposition of the two stimuli

TL;DR

This study investigates how the human body responds to combined small tilts and translations of the support surface, revealing mostly independent responses with some interaction at larger stimuli, possibly due to joint stiffness changes.

Contribution

It provides new insights into the steady-state responses of human stance to combined stimuli and suggests a mechanism involving joint stiffness modulation.

Findings

Responses are mostly independent for small stimuli.

Interaction occurs with larger stimuli.

Joint stiffness modulation may explain observed effects.

Abstract

Upright stance tested with a superposition of support surface tilt and translation. Steady state response is characterized by frequency response function. Interaction between two stimuli absent in most of the cases. Larger stimuli may create interaction. Simulations suggest that the observed effects can be due to joint stiffness modulation.