Distribution of muscle fibre conduction velocity for representative samples of motor units in the full recruitment range of the tibialis anterior muscle

Abstract

were decomposed into single motor unit action potentials, from which the corresponding motor unit RT, 32 MUCV, and action potential amplitude were estimated. Established relations between muscle fiber diameter 33 and CV were used to estimate the fiber size. 34Results: Within individual subjects, the distributions of MUCV and fiber diameters were unimodal and did 35 not show distinct populations. MUCV was strongly correlated with RT (mean (SD) R 2 = 0.7 (0.09), p<0.001; 36 406 motor units), which supported the hypothesis that fiber diameter is associated to RT. 37 Conclusion

The increase in muscle force after 4 weeks of strength training is mediated by adaptations in motor unit recruitment and rate coding

“…; Del Vecchio et al . , ). The motor unit action potentials with high correlation values (>0.7) were visually inspected.…”

“…It has recently been shown that the activity of large populations of motor units can be identified (Holobar & Zazula, 2007;Muceli et al 2015;Farina et al 2016;Negro et al 2016;Del Vecchio et al 2018c) and tracked over multiple sessions (Martinez-Valdes et al 2017) during relatively strong voluntary contractions (70% of maximum, Holobar et al 2014;Del Vecchio et al 2017, 2018b. Once the reliability of the tracking procedure had been confirmed, the present study aimed to quantify the change in discharge characteristics of the same motor units in tibialis anterior after a 4 week strength training intervention with the dorsiflexor muscles.…”

“…The signal was low-pass filtered with a fourth-order, zero-lag Butterworth filter with a cut-off frequency of 15 Hz. Only trapezoidal contractions without any counter-movement action or pre-tension were analysed (Del Vecchio et al 2018c). Before being decomposed into individual motor unit action potentials, the monopolar EMG recordings were bandpass filtered at 20-500 Hz (second-order, Butterworth).…”

“…; Del Vecchio et al . ) and tracked over multiple sessions (Martinez‐Valdes et al . ) during relatively strong voluntary contractions (70% of maximum, Holobar et al .…”

Upcoming Acta Physiologica Award of US$ 100,000.00

“…Manuscripts from 2018 indicate how much attention very young manuscripts are receiving . Listed here are less than half of the original articles receiving double‐digit citations.…”