The risk of falling increases with age and poses a major threat to the independence of older adults. The visual system plays an important role in maintaining balance, so age-related changes to the eye can compromise postural stability. Scientists at the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute have developed a novel night-lighting system that provides visual and spatial cues to promote better postural stability and control. By enhancing the vertical and horizontal elements in the room with lighting, older individuals can better orient themselves to the environment, thereby improving their balance.
Falls risk is higher when a person is changing position, such as standing up or sitting down, especially during the nighttime when visibility and orientation are at minimum, according to Rensselaer Associate Professor Mariana Figueiro, Ph.D., principal investigator on the project.
Her research team designed two night-lighting systems to provide low ambient light that enhances visual elements in the room. The systems use either linear arrays of light-emitting diodes (LEDs) or lasers. One system provided horizontal and vertical cues by placing linear LED arrays along the sides and top of a doorframe. The other system provided laser lines outlining a pathway on the floor.
Working in conjunction with two instructors from The Sage Colleges, Associate Professor Laura Gras and Professor Mary Rea, the LRC research team recently tested the two new lighting techniques with participants ages 65 and older.
First, they assessed the “falls risk” of each participant by obtaining a personal history and by using the Berg Balance Scale, a commonly used method to determine the ability of older adults to keep their balance. This allowed the researchers to group participants into two groups: those with a high risk of falls and those with a low risk of falls.
Then the researchers exposed participants to three different lighting conditions: 1) a high, daylight-like light level provided by ceiling lights, 2) a low light level typical of a conventional wall-plug night-light, and 3) one of the novel night-lighting systems, either using the horizontal and vertical LED lighting or the laser lines outlining the floor pathway.
Using standardized tests for balance and gait measures, the data showed that the enhanced horizontal and vertical LED system enabled both groups to maintain balance significantly better than the wall-plug night-light when transitioning from a sitting to a standing position. While walking, the laser lines outlining the pathway significantly increased velocity and reduced step length variability compared to traditional wall-plug night-lights.
“The study demonstrated that a novel night-lighting system providing robust vertical and horizontal cues is a practical and effective aid in reducing falls risk at night for older adults. We are working closely with industry to share these results in the hope that these techniques will be used by lighting designers and healthcare professionals as preventative measures to decrease falls in older adults,” said Rensselaer Professor Mark Rea, director of the LRC and co-investigator in the project.
The team’s next steps are to test these lighting solutions in other populations that may have compromised balance, such as Alzheimer’s disease patients and stroke patients.
The research results are detailed in two papers, “Lighting and perceptual cues: Effects on gait measures of older adults at high and low risk for falls,” published in BMC Geriatrics, 11:49, and “Lighting for improving balance in older adults with and without risk for falls,” an upcoming paper in Age and Ageing due out later this fall. Both papers were authored by Figueiro, Rea, LRC Research Nurse Barbara Plitnick, Laura Gras and Mary Rea.
This project was funded by a grant from the NIH National Institute of Nursing Research.