Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1990-7-23
pubmed:abstractText
The maximum number of different motor unit action potentials (MUAPs), their firing rates, and total MUAP spikes/second recorded by monopolar needle electrode were determined for the biceps brachii muscle during 45-degree elbow flexion. There were 4.2 +/- 1.6 different MUAPs exceeding 100 microV. Mean firing rate was 10.0 +/- 1.7 Hz, and total MUAP spikes/second were 40.3 +/- 18. Recordings from 16 patients with neurogenic atrophy (NA) and just detectable weakness revealed corresponding values of 3.1 +/- 1.7 different MUAPs, a mean rate of 10.2 +/- 1.5 Hz and 30.6 +/- 19 total MUAP spikes/second, not different from normal. In these patients, increased force of muscle contraction was required to activate high threshold motor units firing at high rates. In each of 4 patients just able to hold the arm against gravity, 1 or 2 "overdriven" motor units firing at a mean rate greater than 20 Hz were recorded. In 8 patients with myopathy and just detectable weakness, greater than 100 total MUAP spikes/second were recorded. Antigravity posture as a reference level of innervation has the advantage that motor unit firing rate is set about that of physiologic tremor (10-13 Hz). Its application was helpful in quantifying recruitment.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0148-639X
pubmed:author
pubmed:issnType
Print
pubmed:volume
13
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
355-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Antigravity posture for analysis of motor unit recruitment: the "45 degree test".
pubmed:affiliation
Department of Neurology, University of Utah School of Medicine, Salt Lake City 84132.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.