One-minute wave in body fluid volume change enhanced by postural
sway during upright standing.
Inamura, Kinsaku, Tadaaki Mano, Satoshi Iwase, Yoshimitsu Amagishi,
and Sadako Inamura.
Department of Autonomic and Behavioral Neurosciences, Division of
Higher Nervous Control, Research Institute of Environmental Medicine,
Nagoya University, Nagoya 464-01, Japan; and Department of Physical
and Health Education in Faculty of Education, Department of Physics
in Faculty of Science, and Medical Care Center, Shizuoka University,
Shizuoka 422, Japan
APStracts 3:0110A, 1996.
To analyze how the one-minute oscillation in postural sway and one
-minute wave in body fluid volume change contribute to human
circulatory homeostasis, several levels of body circumferences, foot
pressure center, electromyograms, and volumes of the leg, abdomen,
and thorax were measured during upright standing for 40 min in 20
healthy young men. Spectral analyses of these parameters revealed
that one-minute rhythm is found in all parameters, and that the one
-minute wave in body fluid volume changes in the lower leg, which
occurs in fluid pooling caused by gravity, propagates upward. Muscle
pumping in the lower leg triggered by the postural sway was found to
increase the power of this one-minute wave. A quantitative analysis
of body circumferences disclosed that the one-minute wave in body
fluid volume change compensates for gravitational downward fluid
shift with the volume of 6.3 +/- 5.0 ml/cycle at the heart level. We
concluded that a coupling mechanism between the one-minute
oscillation in postural sway and the upward propagation of one-minute
wave in body fluid volume change contributes to maintain systemic
blood pressure during upright standing in humans.
Received 20 December 1993; accepted in final form 12 February
1996.
APS Manuscript Number A1212-3.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 March 96