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Principal component analysis of the features of concentric needle EMG motor unit action potentials
Author(s) -
Nandedkar Sanjeev D.,
Sanders Donald B.
Publication year - 1989
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880120406
Subject(s) - motor unit , concentric , principal component analysis , compound muscle action potential , electromyography , biceps , electrophysiology , amplitude , anatomy , biceps brachii muscle , electrodiagnosis , motor unit recruitment , biomedical engineering , physics , mathematics , medicine , physical medicine and rehabilitation , statistics , geometry , optics
Motor unit action potentials (MUAPs) were recorded from the biceps muscle of normal subjects and of patients with nerve of muscle diseases. Principal component analysis of the MUAP amplitude, area, area/amplitude ratio, duration, and the number of turns and phases produced three components that among them contained 90% of the variance of the data set. Thus the dimensionality of data was reduced from six to three. The first component reflected changes in the size of the MU, whereas the second reflected variations in the arrival time at the recording electrode of the action potentials of muscle fibers in the motor unit. The third factor reflected local loss of muscle fibers within the MU territory. Patterns of variations in the three components were different in patients with neuropathy and myopathy.