Lighting for improving balance in older adults with and without risk for falls

SIR—The visual system acquires sensory information about self-position and location of objects in the environment and, together with sensory input from the vestibular and somatosensory systems, helps maintain balance. The dependence on visual information for the maintenance of postural stability and control increases with age due to age-related changes that occur in the vestibular and somatosensory systems [1–10]. Lighting that enhances veridical visual information about the environment for older adults could be a practical and effective intervention to reduce falls risk. Figueiro et al. [11] showed that, in healthy, non-faller older adults, a wall-plug nightlight (NL) was associated with significantly greater sway in the early phase of the sit-to-stand (STS) test than was found with a novel NL system providing low-level ambient illumination and enhanced horizontal and vertical (H/V) visual information. The present study aimed to extend these findings by testing the effectiveness of a similar NL system on another measure, the weight transfer time (WTT), in two groups of older adults, those with and without fall risks. A longer WTT should be associated with more difficulty in getting up [12–14]. It was hypothesised that compared with wall-plug NLs, WTT in the STS test would be better with the novel NL system for both groups, and that the effect would be larger for fallers than for non-fallers. It was also hypothesised that a high contrast (black on white versus white on white) veridical stimulus would be better for postural stability and control than a low contrast stimulus.