Postural Stability of Static Standing on Narrow Platform for Stepladder Safety

Abstract

This research aims to evaluate the stability of static standing posture on narrow platforms for the safe performance of tasks on stepladders. Eleven male participants stood on five platforms that had anterior/posterior widths ranging from 6 cm to 25 cm, and maintained their position for 50 s. The position and velocity of the center of mass and center of pressure（COP）, joint angle, angular velocity, electromyography, and subjective sense of postural instability were analyzed. The results showed that the relative position on the platform, velocity of COP, and subjective sense of postural instability varied as a function of platform width. These results indicate the possibility of losing postural balance on the rungs of commonly used stepladders. To perform tasks safely on stepladders, a stepladder with rungs at least 15 cm or wider is recommended to ensure that the static standing posture is as stable as standing on the ground.