Is there an optimum hardness for bone?

[Tyro]

Obviously, anyone with osteoporosis can tell you that bones can be too soft. But can bones be too hard?

I thought that this may be possible because part of cushioning we get when we do everything from walking to jumping, comes from the flexing/compressing of bones (however small). The rest comes from the joints and the muscles.

What happens in people with an abundance of osteoblasts but too few osteoclasts? Are their bones too hard, and do their joints suffer as a result?

 

[NateTG]

Osteoperosis does not change the hardness of bones, but the density of bones. Bones break more easily because they become thinner, and thus more fragile.

Thus osteoperosis is not a change in the composition of the bone, but instead a reduction in total bone mass, and - more importantly - a loss of bone mass in important locations.

The opposite problem -- excessive buildup of bone -- can occur in the form of bone spurs, and calcification of joints.

 

[Jikx]

"Hard" bones (...) is another way of saying bones which do not flex much when force is exerted on it. And another word of that would be brittle !

Osteoblasts = Bone builders (?)
Osteoclasts = Bone desolvers (?)

With too many osteoblasts compared to osteoclasts, there would be continual secreation of bone matrix (callogen + calcium matrix i believe) wouldn't make the bone "harder".. maybe just bigger and bigger. But i don't think it would occur as bone that is too think would result in the cells being cut off from nutrients and thus die, mantaining an equilibrium in bone building/desolving.

Slightly off topic:

When I was young, I always wondered what would happen if you hit a diamond with a hammer. The responses were :

Geography teacher (geologist): Nothing! Diamonds are the hardest naturally occurring substance on earth..

Physics teacher: If you apply enough energy, it would shatter.

So I would assume that the bone would shatter, rather than just bend for adolescents and fracture for adults.

 

[Achy47]

I'm not well read in this area (in fact not read at all), but it sounds as though this might be related to a lack of tensile strentgh, causing shock to be aborbed by joint tissue.[?]