Animation - Osteoporosis

What factors determine bone strength?

Bone strength is determined by the internal structure, shape, and size of the bone. Bone is dense relative to other tissues and therefore the size and strength of a bone is generally determined by both the need for strength and the cost of increasing the weight of the organism. Strength increases with bone density, however organisms are able to reduce weight and maintain strength by having bones with support systems similar to those of a building or a bridge. Bone strength is also determined by the diameter of the bone. A thicker leg bone is stronger than a thinner leg bone. Again there is a trade off between size and weight. Heavy slow moving animals have thick limb bones while fast moving animals have slender leg bones.

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