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A novel method to attain sinusoidal mechanical responses from single motor units
Author(s) -
Gobbo Massimiliano,
Celichowski Jan,
Krutki Piotr,
DrzymałaCelichowska Hanna,
Solomonow Moshe,
Orizio Claudio
Publication year - 2015
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.24464
Subject(s) - signal (programming language) , total harmonic distortion , physics , distortion (music) , pulse width modulation , modulation (music) , harmonic , acoustics , pulse (music) , control theory (sociology) , mathematics , voltage , computer science , amplifier , control (management) , optoelectronics , cmos , quantum mechanics , artificial intelligence , programming language
: The relationship between output force and motor command depends on the intrinsic dynamic responses of motor units (MUs), which can be characterized by evoking accurate sinusoidal force responses at different frequencies. In this study we sought to determine whether sinusoidal modulation of the stimulation rate of single MUs results in reliable sinusoidal force changes. Methods : Single axons of rat ventral roots were stimulated electrically by changing the pulse rate sinusoidally at different frequency modulation (0.4–1.0–2.0–4.0 H z for slow, 1.0–2.0–4.0–7.0 H z for fast MUs). The twitching sinusoidal force signal was interpolated. We calculated harmonic distortion (HD) and the correlation coefficient ( r ) between theoretical sines and interpolated signals. Results : HD was always <5%, and r was always >0.97. Conclusions : The HD and r‐ values obtained indicate highly reliable sinusoidal responses, which supports the potential use of this method to further characterize the dynamic behavior of single MUs. Muscle Nerve 51 : 134–136, 2015