|
|
||||||||
1Neurological Sciences Institute, Oregon Health & Science University, Portland, Oregon 97006; and 2Departments of Electrical Engineering and Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
Submitted 28 May 2003; accepted in final form 10 September 2003
Upright stance in humans is inherently unstable, requiring corrective action based on spatial-orientation information from sensory systems. One might logically predict that environments providing access to accurate orientation information from multiple sensory systems would facilitate postural stability. However, we show that, after a period in which access to accurate sensory information was reduced, the restoration of accurate information disrupted postural stability. In eyes-closed trials, proprioceptive information was altered by rotating the support surface in proportion to body sway (support surface "sway-referencing"). When the support surface returned to a level orientation, most subjects developed a transient 1-Hz body sway oscillation that differed significantly from the low-amplitude body sway typically observed during quiet stance. Additional experiments showed further enhancement of the 1-Hz oscillation when the surface transitioned from a sway-referenced to a reverse sway-referenced motion. Oscillatory behavior declined with repetition of trials, suggesting a learning effect. A simple negative feedback-control model of the postural control system predicted the occurrence of this 1-Hz oscillation in conditions where too much corrective torque is generated in proportion to body sway. Model simulations were used to distinguish between two alternative explanations for the excessive corrective torque generation. Simulation results favor an explanation based on the dynamic reweighting of sensory contributions to postural control rather than a load-compensation mechanism that scales torque in proportion to a fixed combination of sensory-orientation information.
This article has been cited by other articles:
![]() |
R. A. Roberts Functional Assessment and Management of Peripheral Vestibulopathy Hearing and Hearing Disorders: Research and Diagnostics, November 1, 2009; 13(2): 40 - 53. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. S. Redfern, J. R. Jennings, D. Mendelson, and R. D. Nebes Perceptual Inhibition is Associated with Sensory Integration in Standing Postural Control Among Older Adults J Gerontol B Psychol Sci Soc Sci, September 1, 2009; 64B(5): 569 - 576. [Abstract] [Full Text] [PDF] |
||||
![]() |
U. Nuding, R. Kalla, N. G. Muggleton, U. Buttner, V. Walsh, and S. Glasauer TMS Evidence for Smooth Pursuit Gain Control by the Frontal Eye Fields Cereb Cortex, May 1, 2009; 19(5): 1144 - 1150. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. B Horak, D. M Wrisley, and J. Frank The Balance Evaluation Systems Test (BESTest) to Differentiate Balance Deficits Physical Therapy, May 1, 2009; 89(5): 484 - 498. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Mugge, J. Schuurmans, A. C. Schouten, and F. C. T. van der Helm Sensory Weighting of Force and Position Feedback in Human Motor Control Tasks J. Neurosci., April 29, 2009; 29(17): 5476 - 5482. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Masani, A. H. Vette, N. Kawashima, and M. R. Popovic Neuromusculoskeletal Torque-Generation Process Has a Large Destabilizing Effect on the Control Mechanism of Quiet Standing J Neurophysiol, September 1, 2008; 100(3): 1465 - 1475. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. P Westlake and E. G Culham Sensory-Specific Balance Training in Older Adults: Effect on Proprioceptive Reintegration and Cognitive Demands Physical Therapy, October 1, 2007; 87(10): 1274 - 1283. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Schmid, A. Nardone, A. M. De Nunzio, M. Schmid, and M. Schieppati Equilibrium during static and dynamic tasks in blind subjects: no evidence of cross-modal plasticity Brain, August 1, 2007; 130(8): 2097 - 2107. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Cenciarini and R. J. Peterka Stimulus-Dependent Changes in the Vestibular Contribution to Human Postural Control J Neurophysiol, May 1, 2006; 95(5): 2733 - 2750. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Gruneberg, J. Duysens, F. Honegger, and J.H.J. Allum Spatio-Temporal Separation of Roll and Pitch Balance-Correcting Commands in Humans J Neurophysiol, November 1, 2005; 94(5): 3143 - 3158. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. D Loram, C. N Maganaris, and M. Lakie Human postural sway results from frequent, ballistic bias impulses by soleus and gastrocnemius J. Physiol., April 1, 2005; 564(1): 295 - 311. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Maurer and R. J. Peterka A New Interpretation of Spontaneous Sway Measures Based on a Simple Model of Human Postural Control J Neurophysiol, January 1, 2005; 93(1): 189 - 200. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Jeka, T. Kiemel, R. Creath, F. Horak, and R. Peterka Controlling Human Upright Posture: Velocity Information Is More Accurate Than Position or Acceleration J Neurophysiol, October 1, 2004; 92(4): 2368 - 2379. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |