Electromyographic fatigue threshold of erector spinae muscle induced by a muscular endurance test in health men.
OBJECTIVE
To identify the electromyographic fatigue threshold in the erector spinae muscle.


METHODS
Eight 19 to 24-year-old male volunteers participated in this study, in which surface electrodes were used, as well as a biological signals acquisition module (Lynx) with a sampling frequency of 1000 Hz, a 1000 times gain, a 20 Hz high pass filter and a 500 Hz low pass filter. The test consisted of repeated isometric contractions of the erector spinae muscle in a 45 degrees hip flexion posture, with 30%, 40%, 50% and 60% of the maximum voluntary isometric contraction.


RESULTS
A positive correlation of the RMS (root mean square) value as a function of time was found for most of the subjects with 40% (N = 6), 50% (N = 7) and 60% (N = 8) loads of the maximum voluntary isometric contraction.


CONCLUSIONS
It was concluded, from this study, that the proposed protocol provides evidence, through the electromyographic signal, of the development of fatigue in the erector spinae muscle with loads of 40%, 50% and 60% of the maximum voluntary isometric contraction. The protocol also allows the electromyographic fatigue threshold and its probable applicability in the diagnosis of this phenomenon during repetitive activities to be determined.
Cardozo
A C
AC
Biomechanics Laboratory-Department of Physical Education, Institute of Biosciences-UNESP-Rio Claro. adacar@rc.unesp.br
Gonçalves
M
M
D000328:Adult; D004576:Electromyography; D006801:Humans; D008161:Lumbosacral Region / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D016474:Weight-Bearing