title: On the Modulation of Brain Activation During Simulated Weight Bearing in Supine Gait-Like Stepping.
abstract: To date, the neurophysiological correlates of muscle activation required for weight bearing during walking are poorly understood although, a supraspinal involvement has been discussed in the literature for many years. The present study investigates the effect of simulated ground reaction forces (0, 20, and 40% of individual body weight) on brain activation in sixteen healthy participants. A magnetic resonance compatible robot was applied to render three different levels of load against the feet of the participants during active and passive gait-like stepping movements. Brain activation was analyzed by the means of voxel-wise whole brain analysis as well as by a region-of-interest analysis. A significant modulation of brain activation in sensorimotor areas by the load level could neither be demonstrated during active nor during passive stepping. These observations suggest that the regulation of muscle activation under different weight-bearing conditions during stepping occurs at the level of spinal circuitry or the brainstem rather than at the supraspinal level.
authors.affiliation: Sensory-Motor Systems (SMS) Lab, Department of Health Sciences and Technology, ETH Zurich, ML G 59, Sonneggstrasse 3, 8092, Zurich, Switzerland. lukas.jaeger@hest.ethz.ch.|Clinic of Neuroradiology, University Hospital of Zurich, Zurich, Switzerland. lukas.jaeger@hest.ethz.ch.
authors.forename: Lukas
authors.initials: L
authors.lastname: Jaeger
authors.affiliation: Sensory-Motor Systems (SMS) Lab, Department of Health Sciences and Technology, ETH Zurich, ML G 59, Sonneggstrasse 3, 8092, Zurich, Switzerland.
authors.forename: Laura
authors.initials: L
authors.lastname: Marchal-Crespo
authors.affiliation: Sensory-Motor Systems (SMS) Lab, Department of Health Sciences and Technology, ETH Zurich, ML G 59, Sonneggstrasse 3, 8092, Zurich, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Wolf
authors.affiliation: Division of Vascular Neurology and Neurorehabilitation, Department of Neurology, University Hospital and University of Zurich, Zurich, Switzerland.|Cereneo, Center for Neurology & Rehabilitation, Vitznau, Switzerland.
authors.forename: Andreas R
authors.initials: AR
authors.lastname: Luft
authors.affiliation: Sensory-Motor Systems (SMS) Lab, Department of Health Sciences and Technology, ETH Zurich, ML G 59, Sonneggstrasse 3, 8092, Zurich, Switzerland.|Medical Faculty, Balgrist University Hospital, University of Zurich, Zurich, Switzerland.
authors.forename: Robert
authors.initials: R
authors.lastname: Riener
authors.affiliation: Clinic of Neuroradiology, University Hospital of Zurich, Zurich, Switzerland.|Center of MR-Research, University Children's Hospital, Zurich, Switzerland.
authors.forename: Lars
authors.initials: L
authors.lastname: Michels
authors.affiliation: Clinic of Neuroradiology, University Hospital of Zurich, Zurich, Switzerland.
authors.forename: Spyros
authors.initials: S
authors.lastname: Kollias
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D005684:Gait / Q000502:physiology*; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009068:Movement / Q000502:physiology*; D059906:Neuroimaging; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult
keywords: Body weight support; FMRI; Foot loading; Locomotion; MARCOS; Stepping