title: Alterations in stride-to-stride variability during walking in individuals with chronic ankle instability.
abstract: The aim of this study was to evaluate stride-to-stride variability of the lower extremity during walking in individuals with and without chronic ankle instability (CAI) using a nonlinear analysis. Twenty-five participants with self-reported CAI and 27 healthy control participants volunteered for this study. Participants walked on a motor-driven treadmill for 3 min at their selected speed. Lower extremity kinematics in the sagittal and frontal planes were recorded using a passive retroreflective marker motion capture system. The temporal structure of walking variability was analyzed with sample entropy (SampEn). The CAI group produced lower SampEn values in frontal-plane ankle kinematics compared to the control group (P=.04). No significant group differences were observed for SampEn values of other kinematics (P>.05). Participants with CAI demonstrated less stride-to-stride variability of the frontal plane ankle kinematics compared to healthy controls. Decreased variability of walking patterns demonstrated by participants with CAI indicates that the presence of CAI may be associated with a less adaptable sensorimotor system to environmental changes. The altered sensorimotor function associated with CAI may be targets for clinical interventions, and it is critical to explore how interventions protocols affect sensorimotor system function.
authors.affiliation: University of Kentucky, 900 South Limestone Street, Lexington, KY 40536-0200, United States. Electronic address: masafumi.terada@uky.edu.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Terada
authors.affiliation: Kent State University, MAC Center, P.O. Box 5190, Kent, OH 44242, United States.
authors.forename: Samantha
authors.initials: S
authors.lastname: Bowker
authors.affiliation: University of North Carolina at Charlotte, 9201 University City Blvd, Charlotte, NC 28223-0001, United States.
authors.forename: Abbey C
authors.initials: AC
authors.lastname: Thomas
authors.affiliation: University of North Carolina at Chapel Hill, 26D Fetzer Hall, Chapel Hill, NC 25599, United States.
authors.forename: Brian
authors.initials: B
authors.lastname: Pietrosimone
authors.affiliation: University of Sydney, 75 East St Lidcombe, NSW 2141, Australia.
authors.forename: Claire E
authors.initials: CE
authors.lastname: Hiller
authors.affiliation: University of Toledo, 2801 W Bancroft Street, Toledo, OH 43606, United States.
authors.forename: Martin S
authors.initials: MS
authors.lastname: Rice
authors.affiliation: University of Kentucky, 900 South Limestone Street, Lexington, KY 40536-0200, United States.
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Gribble
mesh_terms: D000328:Adult; D000842:Ankle / Q000502:physiology*; D000843:Ankle Joint / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005080:Exercise Test; D005260:Female; D005684:Gait; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory / Q000379:methods; D009048:Motor Skills; D016059:Range of Motion, Articular; D016138:Walking / Q000502:physiology*; D055815:Young Adult
keywords: 2221; Gait; Joint injury; Movement pattern; Sensorimotor control