The effect of workload, work experience and inclined standing surface on visual spatial perception: Fall potential/prevention implications

Maintenance of upright balance involves interplay between sensory (somatosensory, vestibular and visual) inputs and neuro-motor outputs. Visual spatial perception (VSP) of vertical and horizontal orientation plays a significant role in the maintenance of upright balance. For this experiment, a custom designed computer program randomly generated 42 images of horizontal and vertical lines at various angles for 60 industrial workers (39 ± 9.8 years). Half of the workers had more than three years of experience working on inclined and/or elevated surfaces. The main effects investigated included within subject factors of standing surface inclination (0 ◦ ,1 4 ◦ and 26 ◦ ), job experience (number of months), and postural workload (0%, 50% or 100%). The VSP outcome measure was the count of correct responses to the angles presented. The inclination did not have a significant effect on VSP, but the parameter estimates indicated less correct responses on the inclined surfaces. The postural workload significantly affected the VSP, indicating that with increased workload, less correct responses were given. Finally, job experience was found to improve VSP response scores. In summary, these results indicate that job experience increases accurate VSP, while workloads and inclined work surfaces decrease accurate VSP responses.