The maximum contraction can be measured by force (as with QMA) or by surface electromyography (sEMG). In the latter case, the measurement is called microvolt scaling, where the actual electrical activity generated by the subcutaneous motor units is measured as opposed to the force exerted. Koutedakis, Y., Frischknecht, R., Vrbová, G., Sharp, N.C., and Budgett, R. (1995). Voluntary maximum strength models of the quadriceps in overtrained Olympic athletes. Medical Sci. Sport Exerz. 27, 566–572. doi: 10.1249/00005768-199504000-00015 Keywords: muscle, electrical stimulation, training, voluntary contraction, superimposed stimulation, submaximum intensity, movement, performance In addition, the quality of a training program depends on its intensity (knowing that the quantity of a training program depends on its quantity). Intensity is known to be fundamental to improving motor performance. However, it is not always possible to consistently train high-intensity athletes as they may experience overtraining and chronic fatigue (Lehmann et al., 1992; Anish, 2005; Purvis et al., 2010). Therefore, intensity should be steadily reduced to avoid the adverse consequences of excessive CNS stimulation (Kellmann, 2010; Schaun et al., 2018).

Based on these data, to apply a certain intensity, regularly or occasionally, limiting the involvement of the CNS (i.e. the central factors) while maintaining a strong stimulation of the motor muscles (i.e. the peripheral factors), the superposition of the ES to the VOL can be used as part of training aimed at improving/maintaining muscle strength or endurance. Even if the ES exercise involves the CNS (i.e. corticospinal excitability) in acute use (Chaubet et al., 2013; Kotan et al., 2015) a tiring VOL + ES exercise impaired motor performance (p.B. muscle strength) and motor control (p.B. posture control) less than a VOL fatigue exercise (Paillard et al., 2010). These authors suggested that the contribution of VOL+ ES would limit changes in muscle activation and then central fatigue during tiring exercise with submaximal contraction. In practice, in addition to its positive effects, which lead to greater physiological adaptations compared to VOL, VOL + ES can limit muscle fatigue in acute use, which can reduce the risk of overtraining in chronic applications. Maximum voluntary contractions (VMC) are often used for normalization of electromyography data to allow comparison of signal patterns within and between study participants. Recommendations were made on the types of tasks required to collect CVDs for the forearm muscles, specifically advocating the use of tasks with moments of resistance to get better estimates of forearm CVDs. However, a log detailing the specific tasks to use has not yet been published.

In addition, the effects of member control on the collection of GVCs have not yet been taken into account. Muscle activity was monitored while 23 participants performed nine isometric and resistant tasks. Tasks likely to trigger VCM in the carpi ulnaris flexor, carpi radialis flexor, digitorum superficialis flexor, carpi ulnaris extender, carpi radialis extender, digitorum communis extender and pronator teres were identified. In this way, targeted protocols can be designed to relieve fatigue. Hand dominance had a limited effect, with differences only in the flexors and extensors of the fingers (pp< 0.03). Therefore, the use of the contralateral flexor muscle digitorum superficialis and the extensor muscle digitorum communis to determine activation levels and patterns may not be appropriate. Group refers to ± SD of the force ( A ), voluntary activation ( C. Bezerra, P., Zhou, S., Crowley, Z., Brooks, L., and Hooper, A.

(2009). Effects of unilateral electromyostimulation superimposed on voluntary training on strength and cross-section. Muscle nerve 40, 430–437. doi: 10.1002/mus.21329 Decrease in voluntary strength during persistent maximum voluntary contractions (CVDs) due to changes in the characteristics of the muscles and central nervous system. Central fatigue, a reduction induced by the load of voluntary activation, is affected by several processes. .