Journal of Applied Physiology, Vol 51, Issue 2 262-269, Copyright © 1981 by American Physiological Society
Ventilatory responses to muscular vibrations in healthy humans
Y. Jammes, M. J. Mathiot, J. P. Roll, C. Prefaut, F. Berthelin, C. Grimaud and J. Milic-Emili
In healthy humans, we studied the effect of high-frequency mechanical
vibrations applied unilaterally to the tendon of the biceps or triceps
brachialis on ventilation and the breathing pattern. This stimulus
preferentially activates the muscle spindle afferents. Increase of
respiratory frequency and changes in the ventilatory timing started at the
first or second inspiration during tendon stimulation, and no adaptation
occurred as long as the vibrations continued. The tidal volume and mean
inspiratory flow rate were only enhanced in individuals having
high-frequency breathing during eupnea. The changes in ventilatory
variables were observed when the motor response to vibrations was tested
under isometric or isotonic conditions. Various experimental procedures
enabled us to induce a tonic reflex contraction in either the vibrated
muscle or the antagonist of no reflex contraction in either group of
muscles. In all cases the increase in minute ventilation was identical.
These changes in breathing pattern was not associated with a significant
decrease in alveolar CO2 pressure and did not seem to be responsible for
important variations in respiratory gas exchanges. The response to
high-frequency vibrations was also studied after ventilation was increased
with added dead space. The magnitude of hyperventilation an the pattern of
ventilatory response produced by tendon stimulation did not change with
increased ventilation. In conclusion, the stimulation of muscle spindles in
human induces changes in ventilation and pattern of breathing , and the
occurrence of a reflex muscular contraction does not seem necessary in
order to obtain such effects.
