title: Gait adaptations to simultaneous cognitive and mechanical constraints.
abstract: Previous studies have shown that walking is not a purely automatic motor task but places demands on sensory and cognitive systems. We set out to investigate whether complex walking tasks, as when walking down a steeper gradient while performing a concurrent cognitive task, would demand gait adaptation beyond those required for walking under low-challenge conditions. Thirteen healthy young individuals walked at their self-selected speed on a treadmill at different inclinations (0, -5 and -10%). Gait spatio-temporal measures, pelvis angular excursion, and sacral centre of mass (CoM) motion were acquired while walking or while walking and performing a mental tracking task. Repeated-measures ANOVAs revealed that decreasing treadmill inclination from 0 to -10% resulted in significant decreased walking speed (P < 0.001), decreased stride length (P < 0.001), increased pelvis tilt (P = 0.006) and obliquity variability (P = 0.05), decreased pelvis rotation (P = 0.02), and increased anterio-posterior (A-P) CoM displacement (P = 0.015). Compared to walking alone, walking under dual-task condition resulted in increased step width (P < 0.001), and increased medio-lateral (M-L) CoM displacement (P = 0.039) regardless of inclination grade, while sagittal plane dynamics did not change. Findings suggest that gait adapts differently to cognitive and mechanical constraints; the cognitive system is more actively involved in controlling frontal than sagittal plane gait dynamics, while the reverse is true for the mechanical system. Finally, these findings suggest that gait adaptations maintain the ability to perform concurrent tasks while treadmill walking in healthy young adults.
authors: Movement Science Group, School of Life Sciences, Oxford Brookes University, Headington, Oxford, OX3 0BP, UK. eal-yahya@brookes.ac.uk
authors: Emad
authors: E
authors: Al-Yahya
authors: Helen
authors: H
authors: Dawes
authors: Johnathan
authors: J
authors: Collett
authors: Ken
authors: K
authors: Howells
authors: Hooshang
authors: H
authors: Izadi
authors: Derick T
authors: DT
authors: Wade
authors: Janet
authors: J
authors: Cockburn
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D001288:Attention / Q000502:physiology; D001696:Biomechanical Phenomena; D003071:Cognition / Q000502:physiology*; D056344:Executive Function / Q000502:physiology*; D005080:Exercise Test; D056228:Feedback, Sensory / Q000502:physiology; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008606:Mental Processes / Q000502:physiology; D009483:Neuropsychological Tests; D010388:Pelvis / Q000502:physiology; D004856:Postural Balance / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D013997:Time Factors; D016138:Walking / Q000502:physiology*; D055815:Young Adult