Linked Life Data

9125456

Source:http://linkedlifedata.com/resource/pubmed/id/9125456

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-6-23
pubmed:abstractText
The recruitment order of motor units (MU) was compared during voluntary and electrically induced contractions. With the use of spike-triggered averaging, a total of 302 MUs with recruitment thresholds ranging from 1% to 88% of maximal voluntary contraction were recorded in the human tibialis anterior muscle in five subjects. The mean (+/-SD) MU force was 98.3+/-93.3 mN (mean torque 16.8+/-15.9 mNm) and the mean contraction time (CT) 46.2+/-12.7 ms. The correlation coefficients (r) between MU twitch force and CT versus the recruitment threshold in voluntary contractions were +0.68 and -0.38 (P<0.001), respectively. In voluntary contractions, MUs were recruited in order of increasing size except for only 6% of the cases; whereas, during transcutaneous electrical stimulation (ES) at the muscle motor point, MU pairs showed a reversal of recruitment order in 28% and 35% of the observations, respectively, when the pulse durations were 1.0 ms or 0.1 ms. This recruitment reversal during ES was not related to the magnitude of the difference in voluntary recruitment thresholds between MUs. It is concluded that if the reversal of MU recruitment observed during ES is biophysically controlled by differences in their nerve axon input impedance, in percutaneous stimulation at the motor point, other factors such as the size and the morphological organisation of the axonal branches can also influence the order of activation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0014-4819
pubmed:author
pubmed:issnType
Print
pubmed:volume
114
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
117-23
pubmed:dateRevised
2009-11-11
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Motor unit recruitment order during voluntary and electrically induced contractions in the tibialis anterior.
pubmed:affiliation
Laboratory of Biology, Université Libre de Bruxelles, Brussels, Belgium.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't