Trunk accelerometry as a measure of balance control during quiet standing

The goal was to investigate whether body sway measured by trunk accelerometry during quiet standing could differentiate between young and elderly healthy subjects, and between conditions with eyes open and closed on firm and compliant surfaces. Raw data demonstrated poor discrimination, but horizontal transformation to eliminate a constant gravity component disclosed consistent mean differences across groups (P less than or equal to 0.0025), and also between conditions (P less than or equal to 0.0005), except for the most marginal difference. When drift associated with very low frequency body sway was adjusted for, a significant difference appeared also here (P = 0.001). This study indicates that trunk accelerometry can discriminate between populations and conditions during quiet standing. (C) 2002 Elsevier Science B.V. All rights reserved.