Data from: Fatiguing effects of indirect vibration stimulation in upper limb muscles- post and during isometric contractions superimposed on upper limb vibration

Whole body vibration and upper limb vibration (ULV), continues to gain
popularity as exercise intervention for rehabilitation and sports
applications. However, the fatiguing effects of indirect vibration
stimulation are not yet fully understood. We investigated the effects of
ULV stimulation superimposed on fatiguing isometric contractions using a
purpose developed upper limb stimulation device. Thirteen healthy
volunteers were exposed to both ULV superimposed to fatiguing isometric
contractions (V) and isometric contractions alone- Control (C). Both
Vibration (V) and Control (C) exercises were performed at 80% of the
maximum voluntary contractions. The stimulation used was 30 Hz frequency
of 0.4 mm amplitude. Surface-electromyographic (EMG) activity of the
Biceps Brachii, Triceps Brachii, and Flexor Carpi Radialis were measured.
EMG amplitude (EMGrms) and mean frequency (MEF) were computed to quantify
muscle activity and fatigue levels. All muscles displayed significantly
higher reduction in MEFs and corresponding significant increase in EMGrms
with the V than the Control, during fatiguing contractions (P <
0.05). Post vibration, all muscles showed higher levels of MEFs after
recovery compared to the control. Our results show that near maximal
isometric fatiguing contractions superimposed on vibration stimulation
lead to a higher rate of fatigue development compared to the isometric
contraction alone in the upper limb muscles. Results also show higher
manifestation of mechanical fatigue post treatment with vibration compared
to the control. Vibration superimposed on isometric contraction not only
seems to alter the neuromuscular function during fatiguing efforts by
inducing higher neuromuscular load but also post vibration treatment.