The Microscopic View

We presumably know the basics--bone remodeling, osteoclasts and osteoblasts, mineralization, growth in response to stress, but all that happens before or after the breeze.

This post will try to imagine what occurs during the breeze itself, and per last post we understand there may be differing effects depending on whether we're talking live tissue (collagen, etc.) or mineralized dead tissue or a combo.

The first thing that happens at speed is that there's a hard hoof strike and then 3 pauses before the next strike as the horse flies through the air. I'm assuming that the 12,000 lbs per square inch of the strike that dissipates on through the entire structure causes a couple of things, and we may imagine these by striking together two solid objects or perhaps a limb of a live tree against a solid object.

First there is obvious "vibration". At the cellular/molecular level we may imagine this as oscillation or simply, movement. The cells and molecules move (at whatever distance) vis a vis each other, and said movement is restricted both by the proximity of millions of molecules stuffed into the lattice, and also by the bonding and inherent structure. You can see some of the bonding material in the electron microscopic image above. Without the forces which hold the molecules together, they would simply fly apart.

The second thing that occurs (that I'm able to think of) is heat build up. Chemists and physicists understand that heat is a function of movement--a speed up of electrons, neutrons, etc.--and increases exponentially if it is trapped as when millions of molecules closely encased move in unison. In large animals there is also of course systemic heat build up which contributes.

(Edit 7/9) There is also a third thing that probably occurs, which would be "damage or reshaping of individual molecules/cells" at certain points.

Pretty basic stuff until we consider that:
1. Heat build up weakens bonding material and structure. (picture hard plastic melting).
2. Oscillation and vibration offer minimal harm until the speed overcomes the forces of the bonds.

Continue next post.

Training:
Sat: 7/5: riderless 3 x 2f at 85% speed. They went faster then planned. Both horses walked in the paddock under tack afterwards.
Sun: 7/6 Art trotted 1 mile under tack. Rod walked 5/8 mile under tack.