title: Control entropy identifies differential changes in complexity of walking and running gait patterns with increasing speed in highly trained runners.
abstract: Regularity statistics have been previously applied to walking gait measures in the hope of gaining insight into the complexity of gait under different conditions and in different populations. Traditional regularity statistics are subject to the requirement of stationarity, a limitation for examining changes in complexity under dynamic conditions such as exhaustive exercise. Using a novel measure, control entropy (CE), applied to triaxial continuous accelerometry, we report changes in complexity of walking and running during increasing speeds up to exhaustion in highly trained runners. We further apply Karhunen-Loeve analysis in a new and novel way to the patterns of CE responses in each of the three axes to identify dominant modes of CE responses in the vertical, mediolateral, and anterior/posterior planes. The differential CE responses observed between the different axes in this select population provide insight into the constraints of walking and running in those who may have optimized locomotion. Future comparisons between athletes, healthy untrained, and clinical populations using this approach may help elucidate differences between optimized and diseased locomotor control.
authors: Applied Physiology Laboratory, Eastern Michigan University, Ypsilanti, Michigan 48197, USA.
authors: Stephen J
authors: SJ
authors: McGregor
authors: Michael A
authors: MA
authors: Busa
authors: Joseph
authors: J
authors: Skufca
authors: James A
authors: JA
authors: Yaggie
authors: Erik M
authors: EM
authors: Bollt
mesh_terms: D000054:Acceleration; D001696:Biomechanical Phenomena; D005080:Exercise Test; D005684:Gait / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008297:Male; D008954:Models, Biological; D017711:Nonlinear Dynamics; D010807:Physical Endurance / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology; D012420:Running / Q000502:physiology*; D016138:Walking / Q000502:physiology*; D055815:Young Adult