title: Tactile stimuli affect long-range correlations of stride interval and stride length differently during walking.
abstract: Sensory feedback below the sole of the foot using sub-threshold mechanical noise significantly reduced postural sway in patients with diabetes and stroke. However, the effects of tactile parameters on walking are still elusive. Specifically, the effects of such parameters on human gait variability need to be studied because of possible rehabilitation outcomes in terms of bringing improvement in temporal and spatial gait parameters. The purpose of this study was to investigate whether different frequency and amplitude combinations of vibro-tactile stimulation of feet would affect stride-to-stride variability in healthy young adults. Ten healthy subjects walked on a treadmill at self-selected pace while wearing customized insoles fitted with tactors that vibrated at selected frequencies and amplitudes. The results show that the frequency manipulations of tactile stimulation altered the long-range correlations (LRCs) in stride length while amplitude manipulations affected the LRCs in stride interval without having any effect on the amount of gait variability. Our findings suggest that independent neural mechanisms may be responsible for coordinating LRCs of gait parameters in the spatial and temporal domains.
authors.affiliation: Division of Physical Therapy Education, University of Nebraska Medical Center, Omaha, NE, USA.
authors.forename: Jung Hung
authors.initials: JH
authors.lastname: Chien
authors.affiliation: Department of Kinesiology, Southern Illinois University, Carbondale, IL, USA.
authors.forename: V N Pradeep
authors.initials: VNP
authors.lastname: Ambati
authors.affiliation: Division of Physical Therapy Education, University of Nebraska Medical Center, Omaha, NE, USA.
authors.forename: Chun-Kai
authors.initials: CK
authors.lastname: Huang
authors.affiliation: Department of Biomechanics, Virtual Reality and Robotics Laboratories, Center for Research in Human Movement Variability, University of Nebraska at Omaha, BRB#210, Biomechanics Research Building, 6160, University Drive, Omaha, NE, 68182-0860, USA. mmukherjee@unomaha.edu.
authors.forename: Mukul
authors.identifier: http://orcid.org/0000-0001-9653-0556
authors.initials: M
authors.lastname: Mukherjee
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D056228:Feedback, Sensory / Q000502:physiology*; D005260:Female; D005528:Foot / Q000294:innervation; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D013223:Statistics as Topic; D014110:Touch / Q000502:physiology*; D014732:Vibration; D064232:Visual Analog Scale; D016138:Walking / Q000502:physiology*; D055815:Young Adult
keywords: Detrended fluctuation analysis; Locomotion; Somatosensory; Tactor; Variability