[Dorsal and lumbar paraspinal electromyographic study. Multi-MUP analysis and drawing up normal values in a reference population].
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.
Tomasella
Marco
M
Département d'Electroneuromyographie, CHU Sart Tilman, 4000 Liège, Belgique. m.tomasella@chu.ulg.ac.be
Crielaard
Jean-Michel
JM
Wang
François-Charles
FC
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