|
|
||||||||
Prince of Wales Medical Research Institute, Sydney, New South Wales 2031, Australia
The effect of physiological changes in systemic blood pressure on the force output of working abductor pollicis (AP) muscle was studied in six normal subjects. Supramaximal tetanic stimulation at the ulnar nerve produced repeated isometric contractions at 1-s intervals. Force output declined gradually with time. During the train of contractions, subjects voluntarily contracted the knee extensors for 1 min; this raised systemic blood pressure by 29%. Force output from AP rose in parallel with blood pressure so that 18% of the contraction force lost through fatigue was recovered for each 10% increase in blood pressure. When blood pressure in the hand was kept constant despite the increased systemic pressure, force output did not rise. The results show that muscle performance is strongly affected by physiological changes in central blood pressure and suggest that sensory input concerning the adequacy of muscle performance exerts a feedback control over the increase in systemic blood pressure during muscular activity.
blood pressure control; perfusion pressure; muscle fatigue; muscle force
This article has been cited by other articles:
![]() |
K. L. Walker, N. R. Saunders, D. Jensen, J. L. Kuk, S.-L. Wong, K. E. Pyke, E. M. Dwyer, and M. E. Tschakovsky Do vasoregulatory mechanisms in exercising human muscle compensate for changes in arterial perfusion pressure? Am J Physiol Heart Circ Physiol, November 1, 2007; 293(5): H2928 - H2936. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. S. Maluf and R. M. Enoka Task failure during fatiguing contractions performed by humans J Appl Physiol, August 1, 2005; 99(2): 389 - 396. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |