title: What startles tell us about control of posture and gait.
abstract: Recently, there has been an increase in studies evaluating startle reflexes and StartReact, many in tasks involving postural control and gait. These studies have provided important new insights. First, several experiments indicate a superimposition of startle reflex activity on the postural response during unexpected balance perturbations. Overlap in the expression of startle reflexes and postural responses emphasizes the possibility of, at least partly, a common substrate for these two types of behavior. Second, it is recognized that the range of behaviors, susceptible to StartReact, has expanded considerably. Originally this work was concentrated on simple voluntary ballistic movements, but gait initiation, online step adjustments and postural responses can be initiated earlier by a startling stimulus as well, indicating advanced motor preparation of posture and gait. Third, recent experiments on StartReact using TMS and patients with corticospinal lesions suggest that this motor preparation involves a close interaction between cortical and subcortical structures. In this review, we provide a comprehensive overview on startle reflexes, StartReact, and their interaction with posture and gait.
authors.affiliation: Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Department of Rehabilitation, Nijmegen, The Netherlands. Electronic address: jorik.nonnekes@radboudumc.nl.
authors.forename: Jorik
authors.initials: J
authors.lastname: Nonnekes
authors.affiliation: School of Kinesiology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Mark G
authors.initials: MG
authors.lastname: Carpenter
authors.affiliation: School of Kinesiology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: J Timothy
authors.initials: JT
authors.lastname: Inglis
authors.affiliation: Research Center for Movement Control and Neuroplasticity, Department of Kinesiology, KU Leuven, Leuven, Belgium.
authors.forename: Jacques
authors.initials: J
authors.lastname: Duysens
authors.affiliation: Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Department of Rehabilitation, Nijmegen, The Netherlands; Sint Maartenskliniek Research, Nijmegen, The Netherlands.
authors.forename: Vivian
authors.initials: V
authors.lastname: Weerdesteyn
mesh_terms: D001921:Brain / Q000502:physiology*; D005684:Gait; D006801:Humans; D018482:Muscle, Skeletal / Q000502:physiology; D004856:Postural Balance; D011712:Pyramidal Tracts / Q000502:physiology; D013216:Reflex, Startle / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation
keywords: Gait; Postural control; StartReact; Startle