NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Mapping of electrical muscle stimulation using MRIThe pattern of muscle contractile activity elicited by electromyostimulation (EMS) was mapped and compared to the contractile-activity pattern produced by voluntary effort. This was done by examining the patterns and the extent of contrast shift, as indicated by T2 values, im magnetic resonance (MR) images after isometric activity of the left m. quadriceps of human subjects was elicited by EMS (1-sec train of 500-microsec sine wave pulses at 50 Hz) or voluntary effort. The results suggest that, whereas EMS stimulates the same fibers repeatedly, thereby increasing the metabolic demand and T2 values, the voluntary efforts are performed by more diffuse asynchronous activation of skeletal muscle even at forces up to 75 percent of maximal to maintain performance.
Document ID
19930056552
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Adams, Gregory R.
(NASA John F. Kennedy Space Center Cocoa Beach, FL, United States)
Harris, Robert T.
(NASA John F. Kennedy Space Center Cocoa Beach, FL, United States)
Woodard, Daniel
(NASA John F. Kennedy Space Center Cocoa Beach, FL, United States)
Dudley, Gary A.
(Bionetics Corp., Biomedical and Environmental Labs.; NASA, Kennedy Space Center Cocoa Beach, FL; Ohio Univ., Athens, United States)
Date Acquired
August 16, 2013
Publication Date
February 1, 1993
Publication Information
Publication: Journal of Applied Physiology
Volume: 74
Issue: 2
ISSN: 8750-7587
Subject Category
Aerospace Medicine
Accession Number
93A40549
Funding Number(s)
CONTRACT_GRANT: NAS10-11624
Distribution Limits
Public
Copyright
Other

Available Downloads

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