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

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, 29 subjects engaged in treadmill walking while wearing sandals customized with three 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-min acclimation period of walking with the footwear, subjects were asked to walk on the treadmill for six trials, each 30s 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.

[1]  Attila Priplata,et al.  Noise-enhanced human balance control. , 2002, Physical review letters.

[2]  R. Fitzpatrick,et al.  Age-related differences in walking stability. , 2003, Age and ageing.

[3]  Jeffrey M. Hausdorff.  Gait dynamics, fractals and falls: finding meaning in the stride-to-stride fluctuations of human walking. , 2007, Human movement science.

[4]  S. Studenski,et al.  Too much or too little step width variability is associated with a fall history in older persons who walk at or near normal gait speed , 2005, Journal of NeuroEngineering and Rehabilitation.

[5]  Lee Nolan,et al.  Aging, muscle activity, and balance control: physiologic changes associated with balance impairment. , 2003, Gait & posture.

[6]  S. Brophy,et al.  Interventions for latent autoimmune diabetes (LADA) in adults. , 2011, The Cochrane database of systematic reviews.

[7]  G E Stelmach,et al.  Postural sway characteristics of the elderly under normal and altered visual and support surface conditions. , 1991, Journal of gerontology.

[8]  A. Campbell,et al.  Risk factors for falls in a community-based prospective study of people 70 years and older. , 1989, Journal of gerontology.

[9]  P. Kannus,et al.  Prevention of falls and consequent injuries in elderly people , 2005, The Lancet.

[10]  R. Cumming,et al.  Interventions for preventing falls in the elderly. , 2000 .

[11]  J. J. Collins,et al.  Age-related changes in open-loop and closed-loop postural control mechanisms , 2004, Experimental Brain Research.

[12]  J. Singer,et al.  Applied Longitudinal Data Analysis , 2003 .

[13]  P. Shekelle,et al.  Will my patient fall? , 2007, JAMA.

[14]  D G Lloyd,et al.  Sensori-motor function, gait patterns and falls in community-dwelling women. , 1996, Age and ageing.

[15]  R. Cumming,et al.  WITHDRAWN: Interventions for preventing falls in elderly people. , 2009, The Cochrane database of systematic reviews.

[16]  Farzaneh A. Sorond,et al.  Subsensory vibrations to the feet reduce gait variability in elderly fallers. , 2009, Gait & posture.

[17]  Jeffrey M. Hausdorff,et al.  Gait variability and fall risk in community-living older adults: a 1-year prospective study. , 2001, Archives of physical medicine and rehabilitation.

[18]  Thomas T. Imhoff,et al.  Noise-enhanced information transmission in rat SA1 cutaneous mechanoreceptors via aperiodic stochastic resonance. , 1996, Journal of neurophysiology.

[19]  Peripheral neuropathy. , 1996, Postgraduate medicine.

[20]  H. Ring,et al.  International Rehabilitation Medicine , 2008 .

[21]  Henry Brodaty,et al.  A Multifactorial Approach to Understanding Fall Risk in Older People , 2010, Journal of the American Geriatrics Society.

[22]  Thomas T. Imhoff,et al.  Noise-enhanced tactile sensation , 1996, Nature.

[23]  Jeffrey M. Hausdorff,et al.  Maturation of gait dynamics: stride-to-stride variability and its temporal organization in children. , 1999, Journal of applied physiology.

[24]  J. Judge,et al.  Dynamic balance in older persons: effects of reduced visual and proprioceptive input. , 1995, The journals of gerontology. Series A, Biological sciences and medical sciences.

[25]  Paolo Bonato,et al.  Noise‐enhanced balance control in patients with diabetes and patients with stroke , 2006, Annals of neurology.

[26]  T. M. Owings,et al.  Step width variability, but not step length variability or step time variability, discriminates gait of healthy young and older adults during treadmill locomotion. , 2004, Journal of biomechanics.

[27]  S. Studenski,et al.  Stance time and step width variability have unique contributing impairments in older persons. , 2008, Gait & posture.

[28]  Alen Hajnal,et al.  Transfer of calibration between hand and foot: Functional equivalence and fractal fluctuations , 2011, Attention, perception & psychophysics.

[29]  P C O'Brien,et al.  A 4, 2, and 1 stepping algorithm for quick and accurate estimation of cutaneous sensation threshold , 1993, Neurology.

[30]  B. E. Maki,et al.  Gait Changes in Older Adults: Predictors of Falls or Indicators of Fear? , 1997, Journal of the American Geriatrics Society.

[31]  J. Collins,et al.  Vibrating insoles and balance control in elderly people , 2003, The Lancet.

[32]  R. Guimarães,et al.  Characteristics of the gait in old people who fall. , 1980, International rehabilitation medicine.

[33]  Richard W. Bohannon.  Comfortable and maximum walking speed of adults aged 20-79 years: reference values and determinants. , 1997, Age and ageing.