Linked Life Data

11001508

Source:http://linkedlifedata.com/resource/pubmed/id/11001508

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2001-1-3
pubmed:abstractText
Paralyzed muscle fatigue is the eventual depression of force due to either prolonged or repetitive electrical stimulation of motor units. The robustness and safety of future functional electrical stimulation (FES) systems will rely on their ability to detect the onset of muscle fatigue. The relative degree of muscle activation can be estimated by monitoring the M-wave. The aim of this study was to test a proposed method of quantitative fatigue assessment that detects muscle force output and its corresponding M-wave measured concurrently. The detection of force and M-wave concurrently allows any reduction in muscle force output to be attributed to either changes in the fatigue state of the stimulated muscle or changes in the degree of stimulus activation of that muscle. The fatigue assessment scheme can thereby accommodate the corresponding changes in muscle force caused by an alteration in the stimulation intensity during fatigue. The Extensor Digitorum Communis (EDC), Extensor Pollicis Longus (EPL), and Flexor Pollicis Longus (FPL) muscles of two C5/C6 tetraplegic men were studied. Stimulation recruitment tests over the pulsewidth range from 0 to 200 micros, were performed at intervals during 20 min of maximal stimulation (200 micro/s). Muscle force correlated to the M-wave parameter, second phase area, with mean correlation coefficients of greater than 0.82, when the muscle was in either a nonfatigued or fatiguing state. After the initial force, likely to be primarily due to the fast glycolytic (FG) motor units, had declined the M-wave demonstrated only minor changes throughout the fatigue of muscle force during 20 min of constant maximal stimulation. The second phase area and root-mean-square (rms) of the M-wave [see Fig. 2(a) reflected muscle activation during modulated stimulation and also remained relatively constant during the fatigue-related force decline when the muscle was stimulated at a constant intensity. This detection of M-wave parameters satisfies the defined requirement for a myoelectric parameter that indicates electrical activation, but is relatively invariant to muscular fatigue. Index Terms-Electrical stimulation, electromyography (EMG), functional electrical stimulation (FES), muscle fatigue, spinal cord injury, tetraplegia.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1063-6528
pubmed:author
pubmed:issnType
Print
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
286-96
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Detection of fatigue in the isometric electrical activation of paralyzed hand muscles of persons with tetraplegia.
pubmed:affiliation
Quadriplegic Hand Research Unit, Royal North Shore Hospital, St Leonards NSW, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Validation Studies