@article{MartinezValdesLaineFallaetal.2016,
  author    = {Martinez-Valdes, Eduardo Andr{\´e}s and Laine, C. M. and Falla, D. and Mayer, Frank and Farina, D.},
  title     = {High-density surface electromyography provides reliable estimates of motor unit behavior},
  series = {Clinical neurophysiology},
  volume    = {127},
  journal   = {Clinical neurophysiology},
  publisher = {Elsevier},
  address   = {Clare},
  issn      = {1388-2457},
  doi       = {10.1016/j.clinph.2015.10.065},
  pages     = {2534 -- 2541},
  year      = {2016},
  abstract  = {Objective: To assess the intra-and inter-session reliability of estimates of motor unit behavior and muscle fiber properties derived from high-density surface electromyography (HDEMG). Methods: Ten healthy subjects performed submaximal isometric knee extensions during three recording sessions (separate days) at 10\%, 30\%, 50\% and 70\% of their maximum voluntary effort. The discharge timings of motor units of the vastus lateralis and medialis muscles were automatically identified from HDEMG by a decomposition algorithm. We characterized the number of detected motor units, their discharge rates, the coefficient of variation of their inter-spike intervals (CoVisi), the action potential conduction velocity and peak-to-peak amplitude. Reliability was assessed for each motor unit characteristics by intra-class correlation coefficient (ICC). Additionally, a pulse-to-noise ratio (PNR) was calculated, to verify the accuracy of the decomposition. Results: Good to excellent reliability within and between sessions was found for all motor unit characteristics at all force levels (ICCs > 0.8), with the exception of CoVisi that presented poor reliability (ICC < 0.6). PNR was high and similar for both muscles with values ranging between 45.1 and 47.6 dB (accuracy > 95\%). Conclusion: Motor unit features can be assessed non-invasively and reliably within and across sessions over a wide range of force levels. Significance: These results suggest that it is possible to characterize motor units in longitudinal intervention studies. (C) 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.},
  language  = {en}
}