Vibratory stimulation applied to the sole of the foot shows promise for fall

Findings show that imperceptible vibratory stimulation applied to the soles of the feet improved balance by reducing postural sway and gait variability in elderly study participants. The vibratory stimulation is delivered by a urethane foam insole with embedded piezoelectric actuators, which generates the mechanical stimulation. The study was conducted by researchers from the Institute for Aging Research (IFAR) at Hebrew SeniorLife, Beth Israel Deaconess Medical Center, the Wyss Institute for Biologically Inspired Engineering at Harvard University, and Harvard Medical School, all of Boston, Massachusetts; and Merck Sharpe and Dohme (MSD) Consumer Care, Inc., of Memphis, Tennessee.

These findings are significant because poor balance and an irregular gait are directly related to fall risk. Falls are the leading cause of death from injury among seniors. Risk increases with age and even the fear of falling can reduce quality of life.

1 in 3 seniors falls each year, and 25% of those who fall suffer moderate to severe injuries, such as hip fractures.
Only 25% of hip fracture patients make a full recovery; 40% require nursing home care; and nearly 25% die within 12 months.
By 2020, the annual direct and indirect cost of fall injuries is expected to reach nearly $55 billion.
‘Although loss of sensation in the feet is a common problem among elderly people that can impair balance and gait and result in falls, there are currently no interventions available that can reverse sensory impairments and prevent these dangerous consequences,’ said study lead author Lewis Lipsitz, M.D., Director of the Institute for Aging Research. ‘We were very excited to discover that small amounts of vibratory noise applied to the soles of the feet may be able to do just that.’

This study follows earlier research that looked at how the physical principle of stochastic resonance could be applied to mitigate deficits in the human somatosensory systems that develop due to disease, injury, or age. The somatosensory system informs us about objects in our external environment through touch. Receptors are distributed all over the body and different types of receptors respond to many different kinds of stimuli. Stochastic resonance (SR) is a phenomenon whereby the detectability of weak signals in certain types of systems can be improved through the careful addition of low