Surface EMG mapping of the human trapezius muscle: the topography of monopolar and bipolar surface EMG amplitude and spectrum parameters at varied forces and in fatigue

Muscle Maintenance by Volitional Contraction against Applied Electrical Stimulation

“…The choice may be arguable but seems appropriate as physiological research confirms an association between muscle fatigue and shifts in firing rates towards lower values [7,[12][13][14][15][16][17][18][19][20]. Moreover, regression analyses between the MF and MPF slopes with time were capable of detecting differential responses in the fiber types: with slow twitch fibers showing more resistance to fatigue than the fast twitch fibers [26,27].…”

“…Evaluation of muscle fatigue: EMG power spectral frequency analysis was used to evaluate skeletal muscle endurance [12][13][14][15][16][17][18][19][20]. The median frequency (MF) and the mean power frequency (MPF)…”

Spatial variability in cortex-muscle coherence investigated with magnetoencephalography and high-density surface electromyography

“…Action potentials start to propagate from innervation zones that are typically located in the middle portion of the muscle and prominently visible in bipolar HD-sEMG Sadoyama 1986, 1988). The strongest monopolar sEMG signals are typically measured above the innervation zone, whereas bipolar sEMG signals are reduced in amplitude at the same area (Kleine et al 2000;Roy et al 1986). The locations of the innervation zones vary between individuals (Masuda et al 1985) and muscles (Barbero et al 2012;Rainoldi et al 2004), and they can vary also with respect to the sEMG electrodes in a force leveldependent manner due to the relative motion between the muscle and the skin (Piitulainen et al 2009).…”

Postural strategy and trunk muscle activation during prolonged standing in chronic low back pain patients

“…Surface EMG with monopolar leadings (1 electrode above the muscle and the other not) represent activity from a larger area of muscle fibers than surface EMG from bipolar leadings (both electrodes above the muscle) that mostly represent signals from superficial motor units since the common signal present on both electrodes simultaneously is cancelled out and action potentials traveling over superficial muscle fibers are dominating (Hotta and Ito, 2011;Kleine et al, 2000;. In the trapezius muscle, monopolar and bipolar configurations showed different changes with fatigue (Kleine et al, 2000), while this has not been used to investigate low back muscles yet.The aim of the present study was to investigate if electromyographic manifestations of fatigue occur in deep and superficial lumbar muscles during sustained sitting, whether such fatigue is associated with lumbar muscle variability between-(i.e. the alternating activation) or within sides (i.e.…”