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Reliability of spike triggered averaging of the surface electromyogram for motor unit action potential estimation
Author(s) -
Hu Xiaogang,
Rymer William Z.,
Suresh Nina L.
Publication year - 2013
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.23819
Subject(s) - motor unit , reliability (semiconductor) , spike (software development) , electromyography , action (physics) , neuroscience , physical medicine and rehabilitation , computer science , medicine , psychology , physics , power (physics) , software engineering , quantum mechanics
: The reliability of estimated motor unit parameters using spike triggered averaging (STA) of the surface electromyogram (sEMG) has not been tested thoroughly. We investigated factors that may induce amplitude bias in estimated motor unit action potentials (MUAPs) and shape variations. Methods : An sEMG record was simulated. MUAPs were then estimated from the STA of the simulated EMG. Results : Variations in MUAP duration led to under‐estimation of real MUAP amplitude, while synchronized firing led to over‐estimation of amplitude. Spurious firing resulted in over‐estimation of the amplitude of small motor units but under‐estimation of the amplitude of large ones. Variability in amplitude and high firing rates had minimal influence on amplitude estimation. High firing rates and variation in MUAP duration led to large variations in MUAP shape. Estimation errors also correlated with shape variations. Conclusions : Recommendations to enhance the accuracy of the STA estimates have been proposed. Muscle Nerve 48 : 557–570, 2013