More On Post Race Bounce Back

This 200 nm image from Hansma lab shows a fracture. But what happens if we take a tiny human hand and squeeze these fibrils together, hold them until they stay together (aided by the bone glue proteins, as you see), and then release. How quickly or at what rate do these fibrils "bounce back" to original shape?

Last post indicated temperature effects on this process, and specifically post race heat. What other factors operate?

Certainly the inherent nature of the material, its location and security in space would be significant. A tree branch will rebound more forcefully than a twig. Socking a feather pillow produces rebounding that is only partial--different rates, force and speed of bounce back due to nature, shape and security of materials. Can we conclude anything, then, about bounce back in these bone fibrils shown shown at 200 nm resolution?

Live bone is nearly 50% water and more malleable/less rigid than the dead bone. Again consider a comparison of properties we'd get squeezing and releasing dry pasta noodles compared to moistened noodles, and how this might affect rate of bounce back. Moister will likely bounce back slower!

Conclude that bounce back in live bone instead of being immediate and fast probably will be slow but steady.

How slow? Picture your horse standing there in its stall with the fibrils of its cannons slowly uncorking as the post race time proceeds. High temps will severely limit bounce back in the first 48 hrs. (last post). Thus possibly we'll get bounce back going full bore by day 3 post race!

How does this proceed? Instead of a uniform rate of rebound, possibly the situation would be that some few fibrils--possibly the outer, lighter ones, begin to stir, then move slightly. With each movement surrounding fibrils are influenced causing movement in them to commence. The distances involved are infinitesimally small.

In this scenario--a fairly safe guess that by day 4/post race 50% bounce back has completed with the rebounded fibrils locked back into original pre-race positions. Bounce back inertia stemming from their rigidity, location of roots, etc. has overcome the physical/chemical bindings of the squeezed together lump of fibrils. The forces holding the compressed group are starting to be completely overcome by opposing forces as velcro mineral bumps release and bone glue protein recede!

By day 5 could the fibrils most resistant to bounce back would be starting to stir. These probably are the larger fibrils and those located near the bottom of the pile. By day 6 bounce back would almost be completed.

Total, but plausible speculation, that fits with physical characteristics and also circumstantial evidence we have involving different methods of training and results from those methods. More on the circumstantial evidence later.

To conclude:

48 hrs. post race--minimal bounce back due to high temps.

3 days post race--bounce back in full swing--can we say 50% complete by end of day 3.

4 days post race--the outer fibrils have completed bounce back, the underneath and sturdier fibrils are stirring. End of day, 75% complete.

5 days--stubbornly rooted fibrils are still squeezed. Maybe 85% complete.

6-8 days--some where in there bounce back will be nearing 100%

If we take the horse back to the track for speed work we will presumably reverse bounce back and reinforce the alignment and adherence produced in the race. Next post--are their any other considerations to this, and how might our subsequent speed work operate on the bone fibrils.

Training:

Fri: 7/16: 4 x 4f riderless in light mud as fast as possible, about 80% speed. an attempt to get horse back under control by trot work in the paddock is complete disaster. This horse does not trot. Between his sky gazing caused by his breathing difficulties at the trot, constantly stumbling since he is unable to see where he's going, and repeated spooking since the trees by the paddock are suddenly lines with a pride of lions, trotting or dressage work in the paddock gets us nowhere with Rollin' Rod. This wasted effort, however, leads to a thought process of something that probably will work, to be commenced next day.

Sat. 7/17: 2 miles continuous slow riderless gallop + 4 times walk-trot up and down a safe hill in the pasture. This is our new "method" to get Rod under control. This night we give him the idea, and will start the gallop soon in hopes he'll be doing 1/2f full speed spurts under tack within a couple of weeks, without endangering our rider in process.