Pennsylvania Game News - December 2024 - 62

the shoulder makes lithe running possible
for a white-tailed deer.
Though it may seem counter-intuitive,
it's no coincidence that a gristly front
shoulder of venison yields tender eating
if prepared the right way. When roasted
with moisture, low-and-slow, collagen
proteins within that complex of springy
tissues melt into unctuous butter that
bathes the meat.
released upon impact. It's often employed
to investigate car crashes.
Curious, I used an online calculator
site to work the formula. If I set up the
equation correctly, and if we assume that
the front hooves of a 150-pound deer
leap-running at 35 mph compress the
soil by one inch, the force absorbed by a
front shoulder during a brief fraction of a
moment at impact is something less than
73 tons divided by 2 (two front legs), or
something less than 36.5 tons per shoulder.
In this example, the actual force is
less than the formula's calculated value
because the deer doesn't stop at the end
of a leap; it's still moving and has already
started the next cycle, which means not all
its kinetic energy was released at once, as
happens in a car wreck.
Still, it's an enormous force to absorb.
Deer hunters understand this formula's
validity, having shot bullets weighing
one-third of an ounce at high speed with
lethal effect.
If instead of a free-floating composite
of " soft " tissue, the forelegs were
attached at a rigid joint, that joint would
need to be massively built of heavy bone
to withstand such a shock. A deer can't
afford such bulky weight and still be a
deer. Only the " give " of pliant tissues in
62
Of course, this trait is not unique to
whitetails. All of Earth's ungulates - antelopes,
sheep, horses and bison, even
domestic swine and bovines, share the
advantage of shock-absorber front quarters.
But unless you own a horse, deer
provide our best chance to observe and
appreciate the evolutionary genius of a
floating front shoulder.
Consider the contrast, then, with a
deer's hindquarter design. There, the
femur - upper leg bone - connects directly
to the bony pelvis by a lubricated socket.
Unlike the front shoulder, this rigid link
allows for efficient transfer of force
between bones as the rear leg's muscles
lever against the femur, then transfer that
force to the pelvis and spine to initiate a
leap. Physicists call this " conservation of
energy, " a property essential to the early
stage of a deer's leap cycle.
If the hindquarters were built like the
front, attached by shock-buffering tissues,
the hind legs' " kick " of propulsion would
be lost in a floppy wobble that would get
the deer nowhere. As you stalked through
the woods last fall, the soaring leap of that
buck you startled happened by efficient
transfer of force through the bones of the
hindquarters, followed up by elegant dissipation
of force at the front.
There are more wonders at the rear. Pay
attention the next time you saw through
the femur to cut round steaks from a deer's
hindquarter. External and internal (mus
Pennsylvania Game News - December 2024

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