Posture Sway and the Transition Rate for a Fall

TL;DR

This paper investigates how postural sway relates to fall risk in quiet standing individuals, using ultrasonic measurements and stochastic modeling to quantify transition rates to falling.

Contribution

It introduces a new ultrasonic device for measuring sway and applies stochastic theory to model fall transition rates based on experimental data.

Findings

Root mean square velocity influences fall probability

Kramers transition rate quantifies fall likelihood

Stochastic modeling links sway dynamics to fall risk

Abstract

Postural body sway displacements for quiet standing subjects (measured with a new ultrasonic device) are reported. Two of the well known strategies for balancing, namely ankle and hip movements were probed. The data is modeled using a Fokker-Plank-Langevin stochastic theory. Both analytic and computer simulation techniques are employed. The Kramers transition rate for a fall is expressed as a function of experimental parameters. The root mean square velocity is especially important in determining the fall probability.