More Bone Stuff

So, with 12,000 lbs/sq. inch, or whatever, at speed, what holds it all together? I'll borrow heavily from a very good article:

Bones contain living tissue and non-living substances. Within the "alive bone" are blood vessels, nerves, collagen, and living bone cells that form bone and eat it away called osteoblasts and osteoclasts.

Besides the metabolically active cellular portion of bone tissue, bone is also made up of a matrix (a bonding of multiple fibers and chemicals) of different materials, including collagen fibers and crystalline salts. The crystalline salts deposited in the matrix of bone are composed principally of calcium and phosphate.

The collagen fibers have great tensile strength (to endure stretching forces), while calcium salts having similar physical properties to marble have great compressional strength (to endure squeezing forces). These properties--combined--plus the bondage between collagen fibers and the crystals provide extreme tensile and compressional strength.

NOW HERE IT IS:

Bones are constructed in exactly the same way that reinforced concrete is constructed. The steel of reinforced concrete provides tensile strength, while the cement, sand and rock provide the compressional strength. However, the compressional strength of bone is greater than that of even the best reinforced concrete, and the tensile strength approaches that of reinforced concrete. Neither bone nor concrete has a high degree of torsional strength (to endure twisting).

With this background, I can hopefully pull it all together, explain how warming up affects all this as well as appropriate training. One more post coming on physiology, for the process of ossification provides some interesting info in terms of bone soundness. The illustration below shows a bit the complexity of what we're about. Picture it absorbing the 12,000 lbs/sq. inch:




Training:
Still limping some, Art was exercised several times around the paddock with the older horses and ridden for about 3 minutes. The ground is drying out and think the hoof will come around now. Hopefully we're back in business. Was able to do the first race prep gallop in a week with the oldsters yesterday.