By Emily Delzell
A subsensory level of mechanical noise delivered directly to the foot soles of healthy older adults during walking has the potential to normalize gait variability and possibly reduce the risk of falls, according to research published in July in Gait & Posture.
Investigators at Harvard University in Boston randomized 29 volunteers to six double-blinded trials of treadmill walking wearing sandals customized with three actuators embedded in each sole that produced stochastic-resonance mechanical vibration. In three trials, actuators provided subsensory vibration; in the other trials, they did not. The participants wore reflective markers for kinematic analysis.
The Harvard group reported that stochastic-resonance mechanical stimulation exhibited baseline-dependent effects on spatial stride-to-stride gait variability, slightly increasing variability in individuals with the least baseline variability and producing larger, statistically significant variability reductions in those with greater baseline variability.
The researchers concluded that applying noise-enhanced insoles reduces gait variability in individuals with a more variable gait and that stochastic-resonance mechanical vibrations may provide an effective intervention for preventing falls in healthy older adults during walking.
Stephen DG, Wilcox BJ, Niemi JB, et al. Baseline-dependent effect of noise-enhanced insoles on gait variability in healthy elderly walkers. Gait Posture 2012;36(3):537-540.