Surface electromyography does not accurately reflect rectus femoris activity during gait: Impact of speed and crouch on vasti-to-rectus crosstalk

Regional neuromuscular regulation within human rectus femoris muscle during gait

“…This is major limitation of our study, and we should be careful interpreting the present results. In some previous studies, the potential effect of cross-talk on surface EMG signals of the RF muscle were well documented (Barr et al, 2010;Byrne et al, 2005;Di Nardo and Fioretti, 2013;Nene et al, 2004). While our previous study demonstrated a similar trend in RMS between surface and intramuscular (wire electrode) EMG detected in proximal, middle, and distal regions of the RF muscle during isometric contractions (Watanabe et al, 2012), the effect of cross-talk was not investigated during gait.…”

“…The normal EMG pattern of the RF muscle during gait was discussed in recent studies (Barr et al, 2010;Byrne et al, 2005;Di Nardo and Fioretti, 2013;Nene et al, 2004). Two main burst patterns, one occurring around swing-to-stance transition and the second occurring around stance-to-swing transition, comprise the normal activation pattern of the RF muscle during gait (Annaswamy et al, 1999;Winter and Yack, 1987;Yang and Winter, 1985).…”

“…2 and 3). However, recent studies revealed one burst around stance-to-swing transition in the RF muscle by intramuscular EMG (Barr et al, 2010;Nene et al, 2004). They pointed out that differences in EMG patterns in the literature can be explained by methodological issues in surface EMG, such as cross-talk, since the burst around swing-to-stance transition was shown by surface but not intramuscular EMG (Nene et al, 2004).…”

“…In gait analyses, the RF muscle has often been the subject of intense investigation, since it has been reported that an abnormality in regulation of neuromuscular activation of the RF muscle causes pathological gait in patients with upper motor neuron injuries such as stiff-legged (or -knee) gait (Chapman et al, 2008;Kerrigan et al, 1991;Reinbolt et al, 2008;Riley and Kerrigan, 1998;Sung and Bang, 2000). While numerous studies have investigated the neuromuscular activation pattern of the RF muscle during gait using electromyography (EMG) in able-bodied adults, children, the elderly, and patients (Annaswamy et al, 1999;Barr et al, 2010;Byrne et al, 2005;Chantraine et al, 2005;Di Nardo and Fioretti, 2013;Nene et al, 2004;Sung and Bang, 2000), little attention has been paid to the complicated anatomical characteristics of this muscle. It has been suggested that the RF muscle is comprised of two different muscle-tendon units or neuromuscular compartments, and this anatomical property is referred to as "muscle-withinmuscle" (Balius et al, 2009;Gyftopoulos et al, 2008;Hasselman et al, 1995).…”

Inter-electrode spacing of surface EMG sensors: Reduction of crosstalk contamination during voluntary contractions

“…The issue of crosstalk was discussed, but left inconclusive, stating that there was no general consensus in the literature regarding the quantity and importance of crosstalk (Hermens et al, 2000). Yet, for two decades prior to the SENIAM report, there had been evidence that crosstalk was an issue of concern (Perry et al, 1981;Zipp, 1982;De Luca and Merletti, 1988;Koh and Grabiner, 1992), with additional evidence reported in the past decade (van Vugt and van Dijk, 2001;Farina et al, 2002;Bogey et al, 2003;Johnson and Radtka, 2006;Barr et al, 2010).…”