Switch to
Predicate | Object |
---|---|
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-meshheading:2355948-Action Potentials,
pubmed-meshheading:2355948-Adult,
pubmed-meshheading:2355948-Arm,
pubmed-meshheading:2355948-Electromyography,
pubmed-meshheading:2355948-Female,
pubmed-meshheading:2355948-Humans,
pubmed-meshheading:2355948-Male,
pubmed-meshheading:2355948-Middle Aged,
pubmed-meshheading:2355948-Motor Neurons,
pubmed-meshheading:2355948-Muscles,
pubmed-meshheading:2355948-Neural Conduction,
pubmed-meshheading:2355948-Neuromuscular Diseases,
pubmed-meshheading:2355948-Posture,
pubmed-meshheading:2355948-Recruitment, Neurophysiological
|
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.
|