# A Training System for Human Standing Stability Using Virtual Viscosity Fields

## TL;DR

This paper introduces a personalized training system to improve human standing stability using virtual force feedback, showing effectiveness in both younger and older participants.

## Contribution

The novel contribution is a game-based training system that adapts to individual limits of stability using virtual viscosity fields.

## Key findings

- The system showed two distinct response patterns: expansion of limits of stability and reduction in COP sway.
- Both younger and mature participants demonstrated improved postural stability through individualized training.

## Abstract

Enhancement of postural stability in standing is essential for fall prevention in the context of demographic aging. Against such a background, this study proposes a personalized training system based on individual limits of stability (LOS) for a human standing state. The system evaluates LOS in eight directions using center-of-mass (COM) and center-of-pressure (COP) measurement devices and provides game-based feedback, then promotes balance within the relevant LOS parameters. Loading is individualized by applying greater force to virtual objects as the COP approaches the LOS determined for each subject. Experiments with 32 younger and 19 mature subjects produced evaluations for postural stability index (IPS), LOS area, and COP sway. The results revealed two distinct response patterns: LOS expansion and sway reduction, both observed across younger and mature cohorts. These findings suggest that individualized LOS-based training can be applied to improve standing stability with two distinct strategies. These preliminary findings suggest that individualized LOS-based training is associated with changes in standing stability through two distinct response patterns.