Analysis of Corrective Ankle Torque as an Indicator of Postural Stability in Non-Immersive Virtual Reality Environments

Abstract

Human postural control depends on the continuous integration of visual, vestibular, and somatosensory information; however, its objective evaluation often requires high-cost equipment. The objective of the present study was to quantify alterations in postural control through the dynamic analysis of corrective ankle torque under a progressive multisensory stress protocol.
To this end, 31 young adults were evaluated using a low-cost architecture composed of a Kinect sensor and a custom-developed force platform. The protocol consisted of eight levels that combined Non-Immersive Virtual Reality stimuli and proprioceptive alteration through unstable surfaces.
The extracted metrics included torque magnitude, percentage of maximum functional range usage, and Settling Time (ST). The results demonstrated that surface instability is the factor with the greatest impact, doubling the mechanical demand (from 18% to 38% of the functional range) and significantly increasing ST compared to isolated visual conflicts.
Despite this increase, subjects maintained a wide reserve of physiological stability, without risk of falling. It is concluded that the parametrization of ankle torque and ST constitute highly sensitive biomarkers for characterizing the latency of sensory reweighting. The proposed architecture validates the use of accessible tools for balance monitoring, projecting its future application in personalized neurorehabilitation protocols.