NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
The role of haptic cues from rough and slippery surfaces in human postural controlHaptic information is critically important in complex sensory-motor tasks such as manipulating objects. Its comparable importance in spatial orientation is only beginning to be recognized. We have shown that postural sway in humans is significantly reduced by lightly touching a stable surface with a fingertip at contact force levels far below those physically necessary to stabilize the body. To investigate further the functional relationship between contact forces at the hand and postural equilibrium, we had subjects stand in the tandem Romberg stance while being allowed physically supportive (force contact) and non-physically supportive (touch contact) amounts of index fingertip force on surfaces with different frictional characteristics. Mean sway amplitude (MSA) was reduced by over 50% with both touch and force contact of the fingertip, compared to standing without fingertip contact. No differences in MSA were observed when touching rough or slippery surfaces. The amplitude of EMG activity in the peroneal muscles and the timing relationships between fingertip forces, body sway and EMG activity suggested that with touch contact of the finger or with force contact on a slippery surface long-loop "reflexes" involving postural muscles were stabilizing sway. With force contact of the fingertip on a rough surface, MSA reduction was achieved primarily through physical support of the body. This pattern of results indicates that light touch contact cues from the fingertip in conjunction with proprioceptive signals about arm configuration are providing information about body sway that can be used to reduce MSA through postural muscle activation.
Document ID
20050000266
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Jeka, J. J.
(National Center for Complex Systems, Brandeis University Waltham, MA 02254, United States)
Lackner, J. R.
Date Acquired
August 22, 2013
Publication Date
January 1, 1995
Publication Information
Publication: Experimental brain research. Experimentelle Hirnforschung. Experimentation cerebrale
Volume: 103
Issue: 2
ISSN: 0014-4819
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: 1 F32 NS09025-02
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Neuroscience
Non-NASA Center

Available Downloads

There are no available downloads for this record.
No Preview Available