# Unstable Footwear as a Speed-Dependent Noise-Based Training Gear to Exercise Inverted Pendulum Motion During Walking

## TL;DR

This study investigates how unstable rocker-bottom footwear influences the center of mass motion during walking at different speeds, suggesting it can serve as a noise-based training tool depending on walking speed.

## Contribution

It demonstrates that unstable footwear can modulate body CoM motion during walking, acting as a speed-dependent noise-based training gear, which was not previously established.

## Key findings

- Unstable footwear affects mechanical work during walking.
- It acts as a facilitator at slow speeds.
- It constrains motion at higher speeds.

## Abstract

Previous research on unstable footwear has suggested that it may induce plantar mechanical noise during walking. The purpose of this study was to explore whether unstable footwear could be considered as a noise-based training gear to exercise body center of mass (CoM) motion during walking or not. Ground reaction forces were collected among 24 healthy young women walking at speeds between 3 and 6 km h-1 with control running shoes and unstable rocker-bottom shoes. The external mechanical work, the recovery of mechanical energy of the CoM during and within the step cycles, and the phase shift between potential and kinetic energy curves of the CoM were computed. Our findings support the idea that unstable rocker-bottom footwear could serve as a speed-dependent noise- based training gear to exercise CoM motion during walking. At slow speed, it acts as a stochastic resonance or facilitator, whereas at brisk speed it acts as a constraint.