# Estimation of the Range of Motor Units Firing Rates from EMG Signals using a Fourier-based Power Spectrum Technique

### Armando Malanda, Ignacio Rodríguez, Luis Gila, Javier Navallas, Javier Rodríguez, Pierre A. Mathieu

#### Abstract

A method for estimating the range of the motor units mean firing rates from electromyographic (EMG) recordings is presented. The method is based on classical Fourier spectral estimation techniques and is applied to the 0-50 Hz band of the EMG signal within which the mean MU firing rates are usually observed in sustained contractions. Extensive simulations were performed to account for the influence of different signal characteristics such as the firing rate range (FRR), the number of MUAP trains, the coefficient of variation of the motor unit inter-spike intervals (IPI)) and the noise levels. The number of simulated MUAP trains whose mean firing rate dwelled within the estimated range and the estimation error for the lower and upper extremes of the actual FRR were evaluated. While some peaks were undetected and some inaccuracies in the detected firing rate range were observed, satisfactory results were obtained, as for the vast majority of cases the estimated range corresponded to the actual FRR of the simulated MUAP trains.

#### References

- Basmajian, J., De Luca, J. C., 1985. Muscles alive. Their function revealed by Electromyography, Williams & Wilkins, Baltimore, 5th Edition.
- Merletti, R., Parker, P. A., 2004. Electromyography. Physiology, Engineering and noninvasive applications. IEEE-Press and John Wiley & Sons, New Jersey.
- Ren, X., Hu, X., Wang, Yan, Z., 2006. MUAP extraction and classification based on wavelet transform and ICA for EMG decomposition. Med Biol Eng Comput.
- Zhou, P., Rymer, W. Z., 2004. Can standard surface EMG processing parameters be used to estimate motor unit global firing rate? J Neural Eng.
- Van Boxtel, A., Schomaker, L. R. B., 1983. Motor unit firing rate during static contraction indicated by the surface EMG power spectrum. IEEE Trans Biomed Eng.
- Weyjtens, J. L. F., Van Steenberghe, D., 1984. Spectral analysis of the surface electromyogram as a tool for studying rate modulation: a comparison between theory, simulation and experiment. Biol Cybern.
- Englehart, K. B., Parker, P. A., 1994, 'Single motor unit myoelectric signal analysis with nonstationary data'. IEEE Trans Biomed Eng.
- Lago, P., Jones N. B., 1977, Effect of motor unit firing time statistics on EMG spectra. Med Biol Eng & Comput.
- De Luca, J. C., 1979. Physiology and mathematics of myoelectric signals. IEEE Trans Biomed Eng.
- Christie, A., Inglis, J. G., Kamen, G., Gabriel, D. A., 2009. Relationships between surface EMG variables and motor unit firing rates. Eur J appl Physiol.
- Fuglesang-Frederiksen, A., Ronager, J., 1988. The motor unit firng rate and the power spectrum of EMG in humans. Electroenceph clin Neurophysiol.
- Rodríguez, I., Gila, L., Malanda, et al., 2010. Application of a novel automatic duration method measurement based on the wavelet transform on pathological motor unit action potentials. Clinical Neurophysiology.
- Hayes, M., Statistical Digital Signal Processing and Modeling, John Wiley & Sons, 1996.

#### Paper Citation

#### in Harvard Style

Malanda A., Rodríguez I., Gila L., Navallas J., Rodríguez J. and Mathieu P. (2013). **Estimation of the Range of Motor Units Firing Rates from EMG Signals using a Fourier-based Power Spectrum Technique** . In *Proceedings of the International Conference on Bio-inspired Systems and Signal Processing - Volume 1: BIOSIGNALS, (BIOSTEC 2013)* ISBN 978-989-8565-36-5, pages 377-382. DOI: 10.5220/0004308003770382

#### in Bibtex Style

@conference{biosignals13,

author={Armando Malanda and Ignacio Rodríguez and Luis Gila and Javier Navallas and Javier Rodríguez and Pierre A. Mathieu},

title={Estimation of the Range of Motor Units Firing Rates from EMG Signals using a Fourier-based Power Spectrum Technique},

booktitle={Proceedings of the International Conference on Bio-inspired Systems and Signal Processing - Volume 1: BIOSIGNALS, (BIOSTEC 2013)},

year={2013},

pages={377-382},

publisher={SciTePress},

organization={INSTICC},

doi={10.5220/0004308003770382},

isbn={978-989-8565-36-5},

}

#### in EndNote Style

TY - CONF

JO - Proceedings of the International Conference on Bio-inspired Systems and Signal Processing - Volume 1: BIOSIGNALS, (BIOSTEC 2013)

TI - Estimation of the Range of Motor Units Firing Rates from EMG Signals using a Fourier-based Power Spectrum Technique

SN - 978-989-8565-36-5

AU - Malanda A.

AU - Rodríguez I.

AU - Gila L.

AU - Navallas J.

AU - Rodríguez J.

AU - Mathieu P.

PY - 2013

SP - 377

EP - 382

DO - 10.5220/0004308003770382