Re: Easyboots - shock abosrbtion

[Niccolai Murphy <niccolai_m@yahoo.com>]

I'll put this concept stuff here and the messy stuff under the physics
heading so you can ignore it. Say you are riding on concrete. Not much
give in the surface so the hoof has to take up the impact loads by
deforming all on their own. Stick a pice of rubber between the hoof
and concrete and the loads are reduced. You can get this effect by
placing a rubber mat down on the concrete or putting the rubber on the
hoof.

One thing about this though is that the rubber probably doesn't abosrb
much energy, just stores it and bounces the foot back up again.

You asked for the physics here it is...

The force due to thumping the ground is proportional to acceleration
(in this case decceleration) a part of the hoof as it hits the ground.
Without resorting to impact dynamics we can keep it simple and say
that at a particular point....

Force = mass x acceleration.

On the right hand side of the equation mass is roughly constant (the
mass of the Easyboot being relatively small compared with the mass of
the portion of the horse that is hitting the ground). However
acceleration is different with and without the boot. Without the boot
the distance to deccelerate would be, the give in the ground and the
hoof. With the boot you can add the deformation of the boot to the
distance given to deccelerate. 

So two things are happening;

1) You are increasing the distance to deccelerate (on a hard surface
this effect of the boot would be much greater than on a soft surface).
Sort of like when you step on the brake sooner rather than later when
getting to a traffic light.

2) You are reducing the stiffness of the thing hitting the ground
(putting a thin layer of rubber in the way).

The first effect would be to increase both distance and time to
deccelerate. Time doubly significant than the distance since it's a
squared term, acceleration being the second derivative of distance
with respect to time.

To clarify if it's not familiar to you, 

velocity = distance/time, 
acceleration = velocity/time
=> acceleration = distance/time/time.

The second effect is what drives the time parameter in the first
effect. Will leave the energy equations as an exercise for the student.

Given then that you've reduce the acceleration you've reduce the left
hand side too.




---K S Swigart <katswig@deltanet.com> wrote:
>
> 
> Could somebody explain to me the physics of the shock absorbing
capability
> of Easyboots?
> 
> I can easily see how the provide sole protection, but can't see how
they
> would provide shock absorption to anything other than a minimal
amount.
> Does the plastic that they are made of distibute the shock up around
the
> hoof wall or something.
> 
> Or is it the Easyfoam that provides the shock absorption? (I know
nothing
> about that stuff).
> 
> kat
> Orange County, Calif.
> 
> 

==
http://freeweb.socal.wanet.com/hlurphy/
Nicco Murphy - Poway, San Diego, CA



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