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A.l.hof
06-24-1996, 10:25 PM
Dear biomech- members,
I am very sorry, especially to Jim Dowling
(dowlingj@mcmail.cis.mcmaster.ca), that I forgot to include his
useful response to my question in the response list. It follows here:

>>>>>>>>>>>>>>>
Hello At,

Here are some references that might help you:

Johnston, I.A. (1985). Sustained force development: specializations and
variation among vertebrates. JOURNAL OF EXPERIMENTAL BIOLOGY.
115:239-251.

Pennycuick, C.J. (1992). Adapting skeletal muscles to be efficient. In:
EFFICIENCY, ECONOMY AND RELATED CONCEPTS IN COMPARATIVE ANIMAL
PHYSIOLOGY. (ed: R.W. Blake). Cambridge University Press.

McMahon, T.A. (1984). MUSCLES, REFLEXES AND LOCOMOTION. Princeton
University Press, Princton, New Jersey.

I have always used as a first approximation of human muscle than the rate
of energy consumption for static contractions was about 0.25 * muscle
volume * muscle stress. This means that you need a considerable amount of
muscle contracting at high stress levels to achieve significant oxygen
consumption. As you know, if O2 consumption is to be measured during
steady state, the contraction has to be maintained for several minutes
which limits the stress to values of 30% of maximum or less. I think
that it would be difficult to conduct a VO2 experiment that would get
noticeable increases in cost above the resting level where you could also
identify which muscles were consuming the energy. Incidentally, the 0.25
value that I used above will vary between 0.1 (very slow muscle) to 0.5
(very fast muscle). I hope this helps. Bye for now.

Jim :-)

>>>>>>>>At Hof
Department of Medical Physiology
University of Groningen
Bloemsingel 10
NL-9712 KZ GRONINGEN
The Netherlands
Phone: (31) 50 3632645
Fax: (31) 50 3632751