title: Complex muscle vibration patterns to induce gait-like lower-limb movements: proof of concept.
abstract: Muscle vibrations can induce motor responses and illusions of complex movements. However, inducing gait-like cyclical movements and illusions requires the application of multiple fast alternating vibrations to lower-limb muscles. The objectives were (1) to test the feasibility of delivering complex vibrations in a time-organized manner and (2) to illustrate the possibility of inducing alternate gait-in-place-like movements using these vibrations. Patterns of vibration, produced by 12 vibrators applied bilaterally on the flexor and extensor muscle groups of the lower limbs, were based on normal gait kinematics. We tested 1 s and 2 s cycle patterns of vibration. Vibrator responses were assessed using auto- and crosscorrelations and frequency analyses based on accelerometry measurements, and compared between patterns. High auto- (>0.8) and crosscorrelation (>0.6) coefficients demonstrated a good response by the vibrators to the control signal. Vibrations induced cyclical, low-amplitude stepping-in-place movements that mimicked alternate walking movements with both legs, with 1 s and 2 s cycle durations, in one nondisabled participant and one participant with American Spinal Injury Association Impairment Scale B spinal cord injury standing, relaxed, with body-weight support. Electromechanical vibrators can deliver complex cyclical vibrations and trigger gait-like lower-limb movements. These results warrant the application of these vibration patterns on individuals with sensorimotor impairments to test their potential in gait rehabilitation.
authors.affiliation: Centre de Recherche Interdisciplinaire en Réadaptation (Université de Montréal), Institut de Réadaptation Gingras-Lindsay-de-Montréal, 6300 avenue Darlington, Montréal, QC, H3S 2J4, Canada. cyril.duclos@umontreal.ca.
authors.forename: Cyril
authors.initials: C
authors.lastname: Duclos
authors.forename: Claire
authors.initials: C
authors.lastname: Kemlin
authors.forename: David
authors.initials: D
authors.lastname: Lazert
authors.forename: Dany
authors.initials: D
authors.lastname: Gagnon
authors.forename: Joseph-Omer
authors.initials: JO
authors.lastname: Dyer
authors.forename: Robert
authors.initials: R
authors.lastname: Forget
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D004576:Electromyography; D005260:Female; D005684:Gait; D006801:Humans; D035002:Lower Extremity / Q000503:physiopathology*; D008297:Male; D009068:Movement / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D011187:Posture / Q000502:physiology*; D011434:Proprioception / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000503:physiopathology / Q000534:rehabilitation*; D014732:Vibration
keywords: accelerometry; electromechanical vibrators; gait 
  rehabilitation; humans; kinematics; locomotion; movement 
  illusion; muscle vibration; neuromuscular stimulation; proprioception; spinal cord injury