Format

Send to

Choose Destination
J Neurophysiol. 2016 Feb 1;115(2):967-77. doi: 10.1152/jn.00889.2015. Epub 2015 Dec 9.

Is the notion of central fatigue based on a solid foundation?

Author information

1
Delsys Incorporated, Natick, Massachusetts; Department of Physical Therapy and Athletic Training, Boston University, Boston, Massachusetts pcontessa@delsys.com.
2
Delsys Incorporated, Natick, Massachusetts; Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy; and.
3
Delsys Incorporated, Natick, Massachusetts; Department of Biomedical Engineering, Boston University, Boston, Massachusetts;

Abstract

Exercise-induced muscle fatigue has been shown to be the consequence of peripheral factors that impair muscle fiber contractile mechanisms. Central factors arising within the central nervous system have also been hypothesized to induce muscle fatigue, but no direct empirical evidence that is causally associated to reduction of muscle force-generating capability has yet been reported. We developed a simulation model to investigate whether peripheral factors of muscle fatigue are sufficient to explain the muscle force behavior observed during empirical studies of fatiguing voluntary contractions, which is commonly attributed to central factors. Peripheral factors of muscle fatigue were included in the model as a time-dependent decrease in the amplitude of the motor unit force twitches. Our simulation study indicated that the force behavior commonly attributed to central fatigue could be explained solely by peripheral factors during simulated fatiguing submaximal voluntary contractions. It also revealed important flaws regarding the use of the interpolated twitch response from electrical stimulation of the muscle as a means for assessing central fatigue. Our analysis does not directly refute the concept of central fatigue. However, it raises important concerns about the manner in which it is measured and about the interpretation of the commonly accepted causes of central fatigue and questions the very need for the existence of central fatigue.

KEYWORDS:

central fatigue; interpolated twitch; motor units; voluntary drive

PMID:
26655823
PMCID:
PMC4888967
DOI:
10.1152/jn.00889.2015
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Atypon Icon for PubMed Central
Loading ...
Support Center