Baseline-dependent effect of noise-enhanced insoles on gait variability in healthy elderly walkers

Abstract

The purpose of this study was to determine whether providing subsensory stochastic-resonance mechanical vibration to the foot soles of elderly walkers could decrease gait variability. In a randomized double-blind controlled trial, twenty nine (29) subjects engaged in treadmill walking while wearing sandals customized with three (3) actuators capable of producing stochastic-resonance mechanical vibration embedded in each sole. For each subject, we determined a subsensory level of vibration stimulation. After a 5-minute acclimation period of walking with the footwear, subjects were asked to walk on the treadmill for six (6) trials, each thirty (30) seconds long. Trials were pair-wise random: in three trials, actuators provided subsensory vibration; in the other trials, they did not. Subjects wore reflective markers to track body motion. Stochastic-resonance mechanical stimulation exhibited baseline-dependent effects on spatial stride-to-stride variability in gait, slightly increasing variability in subjects with least baseline variability and providing greater reductions in variability for subjects with greater baseline variability (p < .001). Thus, applying stochastic-resonance mechanical vibrations on the plantar surface of the foot reduces gait variability for subjects with more variable gait. Stochastic-resonance mechanical vibrations may provide an effective intervention for preventing falls in healthy elderly walkers.

Footwear Interventions

“…Insoles administered by Galica et al 10 and Stephen et al 9 provided subsensory vibratory stimulation to the soles of the feet and were worn with sandals. Although Galica et al 10 explored overground walking at a self-selected speed and Stephen et al 9 assessed treadmill walking at a fixed speed, the primary outcome measure in both studies was gait variability.…”

“…1 Increasing evidence suggests that footwear interventions may have the capacity to alter static and dynamic balance performance and gait in older populations, including healthy older people, 2-9 older fallers, [10][11][12] and individuals with age-related sensory impairments 13,14 and chronic musculoskeletal conditions 15 that are associated with balance impairments. In addition to commonly prescribed custommade corrective foot orthoses, numerous other footwear interventions have been developed, including balance-enhancing, 13,14 textured, 5,6,8,11 and vibrating insoles, 7,9,10,12 some of which are not commercially available.…”

“…16 However, recent evidence supports that beneficial sensorimotor alterations may also be an important factor. This new insight is based on growing work exploring the effects of balanceenhancing, 13,14 textured, 5,6,8,11 and vibrating 7,9,10,12 insoles on standing balance and walking in older populations. Applying mechanical or electrical noise signals to plantar mechanoreceptors by way of vibrating insoles is suggested to enhance the detection, transmission, and flow of weak signals due to the effects of aging, thereafter maximizing sensorimotor function.…”

The Importance of Safe Patient Handling to Create a Culture of Safety: An Evidential Review

“…Effects of footwear on gait characteristics have been reported [14,15]. Wearing walking shoes increased gait speed compared to wearing dress shoes [14].…”

“…Wearing walking shoes increased gait speed compared to wearing dress shoes [14]. The application of insoles with a mechanical stimulation to the soles of the feet decreased stride-to-stride variability in step width and stride length [15].…”