Genomes and Genes
Using light to increase visual and perceptual cues and decrease falls risk
Principal Investigator: MARIANA FIGUEIRO
Abstract: DESCRIPTION (provided by applicant): The risk of trips and falls is one of the major challenges facing older persons living at home or in more controlled environments. The goal of this proposed project is to test the effectiveness and feasibility of a lighting solution that can potentially reduce the risk of falls among older adults. This proposed lighting solution will be designed to provide a) illumination in the space, which will help provide visual information about the architectural space to older adults b) distinct vertical and horizontal cues, which will provide older adults with the perception of veridical spatial orientation and c) horizontal cues, which will provide older adults with perception of lines along their desired pathway while they navigate through the space. This is particularly important when they move from a seated or supine to a standing position and when they navigate in the space under dim illumination. Reductions in retinal illumination and the spatial quality of the retinal image are compromised in older adults, likely contributing to falls. Age-dependent changes in the crystalline lens lead to reduced contrast and poorer spatial resolution. This not only reduces visual acuity but also elevates contrast thresholds for all spatial frequencies (Nadler et al., 1990). Under low light levels even high contrast objects, such as door frames and objects on the floor, can drop below threshold, leading to disorientation and falls (De Boer et al., 2004). Neural changes also become problematic for the oldest people in our population. Gibson (1966) describes a number of higher-order perceptual phenomena that can be compromised in seniors. In particular, an inability to orient oneself with respect to the environment becomes more common with aging. Together, these changes may contribute significantly to the increased incidence of falls by older people. The Lighting Research Center (LRC) at Rensselaer Polytechnic Institute and researchers at The Sage Colleges plan to test the effectiveness of a proposed practical lighting solution designed to provide illumination and high-contrast spatial cues to improve postural control and stability, and reduce risk of falls among older adults. Static balance will be assessed when subjects are transferring from a sitting to a standing position by using the sit to stand (STS) test;dynamic balance will be assessed when subjects are walking by the Timed "Up and Go" test (TUG), and stride length and gait velocity measurement will be obtained using the GAITRite Mat System. Positive results obtained with this feasibility study will prompt a larger study designed to investigate the effectiveness of this lighting solution in reducing fall risk among older adults living at home and in a more controlled environment. The lighting solution proposed here should enable older adults to get out of bed at night more quickly and securely and to navigate safely through architectural spaces while minimizing sleep disruptions caused by turning on bright lights at night. PUBLIC HEALTH RELEVANCE: The risk of trips and falls is one of the major challenges facing older persons living at home or in more controlled environments. The goal of this project is to test the effectiveness of a lighting solution that provides visual and perceptual information to improve postural control and stability of older adults while transitioning from a seated to a standing position and while navigating in the space.
Funding Period: ----------------2009 - ---------------2011-
more information: NIH RePORT
- Lighting and perceptual cues: effects on gait measures of older adults at high and low risk for fallsMariana G Figueiro
Lighting Research Center, Rensselaer Polytechnic Institute, 21 Union Street, Troy, NY 12180, USA
BMC Geriatr 11:49. 2011..As a person ages, gait becomes slower and stride becomes shorter, especially in dimly lighted environments. Falls risk has been associated with reduced speed and increased gait variability...