title: [Dorsal and lumbar paraspinal electromyographic study. Multi-MUP analysis and drawing up normal values in a reference population].
abstract: OBJECTIVE
  The aim of this study was to contribute to draw up reference values relating to electromyographic (EMG) parameters in dorsal and lumbar paraspinal muscles.
  
  
  METHODS
  75 healthy subjects without back pain underwent electromyography of multifidus bundles, which are innervated uni-segmentally by the dorsal ram of the spinal nerve. T8, L3, L4, L5 and S1 myotomes were systematically explored. Output variables were spontaneous denervation activity and quantitative EMG data obtained by multi-MUP (Motor Unit action Potential) analysis.
  
  
  RESULTS
  No abnormal insertional or spontaneous activity (such as fibrillation, positive sharp waves or fasciculation) was recorded at rest. Neither sex nor age influenced motor unit action potential features in our series. Reference values were drawn up for T8 and L5 segmental levels using the mean values of 20 motor unit potentials in each patient studied, the reference interval being defined by the lower and the upper outlier limits on individual values.
  
  
  CONCLUSIONS
  This study offers reference data to electromyographers to help better identifying possible myogenic or neurogenic pathological changes, especially in lumbosacral radiculopathies.
authors.affiliation: Département d'Electroneuromyographie, CHU Sart Tilman, 4000 Liège, Belgique. m.tomasella@chu.ulg.ac.be
authors.forename: Marco
authors.initials: M
authors.lastname: Tomasella
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Crielaard
authors.forename: François-Charles
authors.initials: FC
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D001415:Back; D003627:Data Interpretation, Statistical; D004576:Electromyography / Q000592:standards*; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology*; D009121:Muscle Denervation; D018482:Muscle, Skeletal / Q000294:innervation* / Q000502:physiology*; D012016:Reference Values