sEMG feature analysis on forearm muscle fatigue during isometric contractions

Abstract

In order to detect and assess the muscle fatigue state with the surface electromyography (sEMG) characteristic parameters, this paper carried out a series of isometric contraction experiments to induce the fatigue on the forearm muscles from four subjects, and recorded the sEMG signals of the flexor carpi ulnaris. sEMG’s median frequency (MDF) and mean frequency (MF) were extracted by short term Fourier transform (STFT), and the root mean square (RMS) of wavelet coefficients in the frequency band of 5–45 Hz was obtained by continuous wavelet transform (CWT). The results demonstrate that both MDF and MF show downward trends within 1 min; however, RMS shows an upward trend within the same time. The three parameters are closely correlated with absolute values of mean correlation coefficients greater than 0.8. It is suggested that the three parameters above can be used as reliable indicators to evaluate the level of muscle fatigue during isometric contractions.

Keywords

muscle fatigue / isometric contraction / time-frequency spectrum analysis / median frequency / mean frequency / root mean square / correlation

References

[1] Avela J, Kyröläinen H, Komi P V. Neuromuscular changes after long-lasting mechanically and electrically elicited fatigue [J]. European Journal of Applied Physiology, 2001, 85(3/4): 317-325.

[2] Xiang Z, Tian G, Xu W, et al. Load on bicycle frame during cycling with different speeds and gestures [J]. Transactions of Tianjin University, 2011, 17(4): 270-274.

[3] Enoka R M, Duchateau J. Muscle fatigue: What, why and how it influences muscle function [J]. The Journal of Physiology, 2008, 586(1): 11-23.

[4] Enoka R M, Baudry S, Rudroff T, et al. Unraveling the neurophysiology of muscle fatigue [J]. Journal of Electromyography and Kinesiology, 2011, 21(2): 208-219.

[5] Disselhorst-Klug C, Schmitz-Rode T, Rau G. Surface electromyography and muscle force: Limits in sEMG-force relationship and new approaches for applications [J]. Clinical Biomechanics, 2009, 24(3): 225-235.

[6] Cashaback J G, Cluff T, Potvin J R. Muscle fatigue and contraction intensity modulates the complexity of surface electromyography [J]. Journal of Electromyography and Kinesiology, 2013, 23(1): 78-83.

[7] Cifrek M, Medved V, Tonković S, et al. Surface EMG based muscle fatigue evaluation in biomechanics [J]. Clinical Biomechanics, 2009, 24(4): 327-340.

[8] Ito K, Hotta Y, Abe T. Detection of muscle fatigue during low-level isometric contraction using recurrence quantification analysis[C]. International Federation for Medical and Biological Engineering (IFMBE). Beijing, China, 2013

[9] Zaman S A, Macisaac D T, Parker P A. Repeatability of surface EMG-based single parameter muscle fatigue as-sessment strategies in static and cyclic contractions [C]. 33rd Annual International Conference of the IEEE EMBS. Boston, USA, 2011

[10] Duchêne J, Goubel F. Surface electromyogram during voluntary contraction: Processing tools and relation to physiological events [J]. Critical Reviews in Biomedical Engineering, 1993, 21(4): 313-397.

[11] Rainoldi A, Galardi G, Maderna L, et al. Repeatability of surface EMG variables during voluntary isometric contractions of the biceps brachii muscle [J]. Journal of Electromyography and Kinesiology, 1999, 9(2): 105-119.

[12] Beck T W, Housh T J, Johnson G O, et al. Comparison of Fourier and wavelet transform procedures for examining the mechanomyographic and electromyographic frequency domain responses during fatiguing isokinetic muscle actions of the biceps brachii [J]. Journal of Electromyography and Kinesiology, 2005, 15(2): 190-199.

[13] Barandun M, von Tscharner V, Meuli-Simmen C, et al. Frequency and conduction velocity analysis of the abductor pollicis brevis muscle during early fatigue [J]. Journal of Electromyography and Kinesiology, 2009, 19(1): 65-74.

[14] Crenshaw A G, Karlsson S, Gerdle B, et al. Differential responses in intramuscular pressure and EMG fatigue indicators during low-vs. high-level isometric contractions to fatigue [J]. Acta Physiologica Scandinavica, 1997, 160(4): 353-361.

[15] Zhang Z G, Liu H T, Chan S C, et al. Time-dependent power spectral density estimation of surface electromyography during isometric muscle contraction: Methods and comparisons [J]. Journal of Electromyography and Kinesiology, 2010, 20(1): 89-101.

[16] Yan Z, You X, Chen J, et al. Motion classification of EMG signals based on wavelet packet transform and LS-SVMs ensemble [J]. Transactions of Tianjin University, 2009, 15(4): 300-307.

[17] Soo Y, Sugi M, Yokoi H, et al. Simultaneous measurement of force and muscle fatigue using frequency-band wavelet analysis [C]. 30th Annual International Conference of the IEEE EMBS. Vancouver, Canada, 2008

[18] Logan M. Biostatistical Design and Analysis Using R: A Practical Guide [M]. 2010, Oxford, UK: Wiley-Blackwell.