VESTIBULAR-SOMATOSENSORY INTERACTION FOR HUMAN POSTURE

Project: Research project

Description

The long-term goal of this study is to better understand how vestibular
and somatosensory information are integrated to control human postural
stability. The specific aims of this proposal are: 1) to determine how
bilateral loss of vestibular function affects postural responses to
surface and vibratory perturbations; 2) to determine whether
somatosensory disruption affects postural responses to head and
vestibular perturbations; 3) and to characterize how vestibular and
somatosensory inputs interact in the control of postural stability. Although vestibular and somatosensory loss are known to cause severe
postural instability, the relationships between these sensory systems in
normal and disordered postural control are not well understood.
Understanding how these sensory systems interact together is important
because multisensory deficits involving both the vestibular and
somatosensory systems are the most common etiology for "nonspecific"
balance problems in the elderly, affecting the majority of people over
70 years old. Compensating for vestibular or somatosensory loss depends
upon complex interactions of remaining senses in the central nervous
system, yet there are few studies focused on these sensory interactions
in humans. We hypothesize that: 1) the loss of peripheral vestibular function in
patients with vestibular disorders results in an increased gain of
postural responses elicited by somatosensory inputs; 2) that disruption
of somatosensory function in patients with diabetic peripheral neuropathy
or in healthy subjects standing on altered surfaces results in increased
gain of postural responses elicited by vestibular inputs; and 3) that
combinations of vestibular and somatosensory perturbations to posture
interact in complex ways in healthy subjects. Somatosensory perturbations to stability will be induced mechanically
with a moveable platform and directly by muscle vibration. Vestibular
perturbations will be induced mechanically with an air-jet head perturber
and directly with galvanic stimulation to the mastoid processes.
Postural responses of the legs, trunk, and head will be quantified by
muscle activation patterns, surface reactive forces under each foot, and
kinematics of body motion. The influence of vision will be eliminated
by blindfolding all subjects. These studies will provide insight into the interactive mechanisms
underlying effective compensation for vestibular and somatosensory
deficits. A better understanding of vestibular-somatosensory
interactions will allow us to better identify abnormal sensory
interactions in patients with balance problems and to develop effective
approaches to facilitate sensory compensation.
StatusFinished
Effective start/end date12/1/923/31/04

Funding

  • National Institutes of Health
  • National Institutes of Health: $383,039.00
  • National Institutes of Health
  • National Institutes of Health: $171,611.00
  • National Institutes of Health: $372,904.00
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $204,768.00
  • National Institutes of Health: $359,120.00

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Posture
Head
Research Personnel
Healthy Volunteers
Foot
Leg
Muscles
Mastoid
Diabetic Neuropathies
Vibration
Biomechanical Phenomena
Touch
Torque
Air
Fingers
Inpatients
Rehabilitation
Light

ASJC

  • Medicine(all)
  • Neuroscience(all)