title: Modulation of afferent inflow during the control of balancing tasks using the lower limbs.
abstract: This study investigated the control of sensory inputs during the performance of an inverted-pendulum balancing task. Experiments were conducted to examine modulation of proprioceptive inputs during balance tasks of varying difficulty. It was hypothesized that proprioceptive inputs to both spinal and cortical levels would be facilitated during a challenged balance task. In contrast, during challenged balance control, results revealed task-specific facilitation of sensory inputs to the cortex and inhibition of the spinal reflex pathway. Observations of increased transmission of proprioceptive inputs to the cortex and decreased transmission at the spinal level suggest that the cortex plays an important role in challenged balance, whereas the role for the spinal stretch reflex appears to be less important.
authors.affiliation: Graduate Department of Rehabilitation Science, Department of Physical Therapy, University of Toronto, 8th Floor, 500 University Ave., Toronto, Ontario, Canada M5G 1V7. w.mcilroy@utoronto.ca
authors.forename: William Evans
authors.initials: WE
authors.lastname: McIlroy
authors.forename: Darcy Claire
authors.initials: DC
authors.lastname: Bishop
authors.forename: William Richard
authors.initials: WR
authors.lastname: Staines
authors.forename: Aimee Jennifer
authors.initials: AJ
authors.lastname: Nelson
authors.forename: Brian Edward
authors.initials: BE
authors.lastname: Maki
authors.forename: John Dennis
authors.initials: JD
authors.lastname: Brooke
mesh_terms: D000328:Adult; D000344:Afferent Pathways / Q000502:physiology; D000842:Ankle / Q000502:physiology; D002540:Cerebral Cortex / Q000502:physiology; D005073:Evoked Potentials, Somatosensory; D006181:H-Reflex / Q000502:physiology; D006801:Humans; D007866:Leg / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology; D004856:Postural Balance / Q000502:physiology*; D011434:Proprioception / Q000502:physiology*; D013116:Spinal Cord / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology; D013979:Tibial Nerve / Q000502:physiology