Three dimensional validation of an instrumented handrail for stair gait.

Some studies have used load cells (LC) to measure the force applied to horizontal handrails, but no work has validated an inclined set-up that can be used to bring new insights into handrail use during staircase gait. The aim of this study was to validate the accuracy of an inclined handrail set-up instrumented with LC. A handrail set-up designed to be easily reconstructed and integrating two commercial LC is proposed. Twenty points were tested along the handrail, with four reference weights in the three orthogonal directions of the sensors (Medio-Lateral, Antero-Posterior, Vertical). For each direction, the percentage (%) of error and the cross-talk between the known and recorded forces were calculated. A linear regression of the % error was performed to evaluate measurement accuracy in relation to point of application along the handrail. The current easily replicated set-up of an inclined handrail showed accurate measures with low cross-talk. The percentage of error and cross-talk were below 3.7% and 3.7%, respectively, consistent with previous studies evaluating inclined handrail with other methods. The error and cross-talk were greater in the Medio-Lateral and Antero-Posterior directions. The error in the Antero-Posterior direction was larger over the upper part of the handrail.