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Jon Linderman said:

> Show me the evidence where quote unquote live mass
> negates the affects of mass on energetics?   I agree
> properly riding a horse reduces effects of mass  in terms
> of torque and concussion.  Practically speaking a well
> balanced HW can provide less trauma than a sloppy
> floppy LW, fine, no worries mate, now back to energetics.
> That horse carrying a well balanced HW still carried more
> mass, resulting in increased energy expenditure, heat storage,
> CV expenditure, etc.
Since energy expended is a function of work performed and horses are,
from a mechanical movement standpoint, an assortment of levers and
pulleys, the amount of work required to move the mass forward is as much
a function of how those levers and pulleys work in relation to each
other as it is the static value of the mass.

Because, get this, any time a horse moves he is both pushing and braking
at the same time (mostly, although this is a big generalization, a horse
pushes with its hind end and brakes with its front end).  Some horses
are more naturally efficient movers (ie they do more pushing and less
braking) so two horses with exactly the same mass (even unmounted) can
do very different amounts of work, even at the same speed, because of
the way that the mechanism is constructed (from a musculoskeletal
standpoint) and because of the way they have learned to move their feet
(since how horses push and/or brake is very much a function of where
they put their feet).

On any one day, a rider cannot affect the underlying musculoskeltal
system of a horse; however, a rider over time can change his horse's
musculoskeletal system by building different muscles on the same frame.
A competent rider builds the muscles in his horse that make the horse a
more efficient mover.

However, even on a horse that he has not conditioned himself, EVERY
rider has an effect, every step of the way, on where and when the horse
puts its feet on the ground. Thinking riders effect this deliberately,
however, even the most incompetent and oblivious of riders WILL have an
effect on the where and when the horse places its feet in order to
balance itself and its load.  This effect will change the amount of
pushing or braking the horse does on every stride and has an HUGE impact
on the amount of work performed.

The mechanics of the mathematics of figuring this out is FAAAAAAAR too
complicated to come up with any numbers, but rest assured the effect of
the balance of a dynamic load that is constantly shifting does have an
effect on the amount of work performed, and therefore on the amount of
energy expended.

To best understand this, it is important to understand the underlying
concept that horses are doing some amount of braking on every stride,
and this amount of braking is a function of the timing and placement of
the feet, even on the same exact horse.

This is not an effect that is confined to horses.  Gait analysis in
elite human athletes is a common practice, because it is fully
understood that some gaits are more effecient that others and that even
bipeds can change the amount of work performed by changing the timing
and placement of their feet.  I have even observed it myself when I went
out as the "sweep" official on a trail run with the local running group.
The tail end runners (i.e. the ones that I saw the most of) were braking
on every stride, and I could hear it as they ran as their feet would hit
the ground and skid forward before pushing off, that skidding forward
against the ground caused deceleration on every step.

In quadripeds where the mass of the horse is not supported by the legs
(and that have a HUGE lever on the front called a neck and a head), the
effect of changes in placement of the feet on work performed is even
greater.

And rest assured, the rider's skill, in addition to his balance, has a
huge effect on how, when and where the horse places its feet, on every
stride, and this effect becomes exaggerated when the footing and terrain
become uneven.  However, this effect is incalculable.

kat
Orange County, Calif.




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