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Re: Muscle work



At 12:02 AM 7/23/01 -0700, Tucker Hiatt wrote:
I'm still not understanding why the pull-up
upstroke seems to require more muscle work than the downstroke.

And I'm still not understanding why we should not expect it to be more.
After all, it _is_ more. If we take the usual physics definition of work,
it is 200% more.

-- Does your car get equal gas mileage going uphill and downhill? Is there
any reason to expect it should?

I can't even figure out whether we are discussing the basic physics, or the
perceptual physiology.

-- Does anybody think there is a simple relationship between the two? Is
there a physiological perception that bears a relevant useful relationship
to (F dot dx)? Is there a perception that bears a relevant useful
relationship to (|F dot dx|)? If so, please explain.

Furthermore.....

-- Why are we still talking about work? I warned in my previous note that
this is precisely the sort of situation where it doesn't make sense to
fixate on work to the exclusion of other types of energy transfer and energy
conversion.

================

Suggestion: Let's approach this using the methods of physics. Let's at
least try to make things a little more explicit.

Write down some equations. For example, try filling in the blanks below.
where (f) calls for a physics formula, and (n) calls for a number with
appropriate dimensions.

the perception we are talking about is called _____________
and is roughly proportional to some physical quantity
namely _______________(f)
because ________________________________________

this physical quantity depends on __________ plus _________
plus __________(f)

on the upstroke this evaluates to ______________(n)

on the downstroke this evaluates to ______________(n)

Therefore,
perception on upstroke is predicted to be _____________

perception on downstroke is predicted to be _____________

Finally,
is the actual perception consistent with this prediction?