Journal
EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY
Volume 114, Issue 8, Pages 1645-1655Publisher
SPRINGER
DOI: 10.1007/s00421-014-2893-y
Keywords
Training adaptation; Neural drive; EMG amplitude; Computer simulation
Categories
Funding
- Bulgarian National Science Fund [DMU03/75]
Ask authors/readers for more resources
Purpose To test the validity of using the increase in surface EMG as a measure of neural adaptation during the early gains in strength. Methods Simulation of EMG signals detected by surface bipolar electrode with 20-mm inter-pole distance at different radial distances from the muscle and longitudinal distances from the end-plate area. The increases in the root mean square (RMS) of the EMG signal due to possible alteration in the neural drive or elevation of the intracellular negative after-potentials, detected in fast fatigable muscle fibres during post-tetanic potentiation and assumed to accompany post-activation potentiation, were compared. Results Lengthening of the intracellular action potential (IAP) profile due to elevation of the negative after-potentials could affect amplitude characteristics of surface EMG detected at any axial distance stronger than alteration in the neural drive. This was irrespective of the fact that the elevation of IAP negative after-potential was applied to fast fatigable motor units (MUs) only, while changes in frequency of activation (simulating neural drive changes) were applied to all MUs. In deeper muscles, where the fibre-electrode distance was larger, the peripheral effect was more pronounced. The normalization of EMG amplitude characteristics to an M-wave one could result only in partial elimination of peripheral factor influence Conclusions T he increase in RMS of surface EMG during the early gains in strength should not be directly related to the changes in the neural drive. The relatively small but long-lasting elevated free resting calcium after high-resistance strength training could result in force potentiation and EMG increase.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available