According to
certain researches of the Case Western Reserve University, it has been found out
that the actual reason for backbone fractures is the evolution of our vertebrae
for upright walking, not merely due to osteoporosis.
We, the Homo sapiens have much larger and porous
vertebrae encased in a thinner shell as compared to the other primates.
But this evolution is found to be effective only till ageing, after which we generally lack the strength and calcium to feed our bones thus suffering bone loss.But apes on the other hand have their vertebrae intact even with ageing and bone loss because of their supportive thicker vertebral shells.
But this evolution is found to be effective only till ageing, after which we generally lack the strength and calcium to feed our bones thus suffering bone loss.But apes on the other hand have their vertebrae intact even with ageing and bone loss because of their supportive thicker vertebral shells.
In the words
of Meghan Cotter, an instructor in anatomy at Case Western Reserve University ,”In
evolution we have great adaptations, but there is sometimes a tradeoff. The structure
is great for walking around , but not good when you have osteoporosis.”
Prof. Bruce
Latimer in his studies on early hominids found fractures in the vertebrae of human skeletons but not
in ape remains in the Hamann-Todd collection. Cleveland Museum of Natural
History contains a collection of more than 3000 human and 1200 ape specimens.
The researchers
used CT scans, micro CT scans and computer modeling to compare the detailed structure
, shape and strength of the 8th thoracic vertebrae of humans,
gorillas, chimpanzees and organutans. The 8th vertebrae was taken
into account because its one of the bones most often fractured in humans with
osteoporosis.It was found
that the porous bone of vertebrae dissipates impact and was useful only for
mitigating the forces of walking on two feet, protecting cartilage in joints and
the discs between vertebrae.
Many recent
researches have suggested that the modern lifestyle is also responsible for the
susceptibility to bone loss and damage.
The fossil records
ain’t complete but sufficient to conclude that the human forebearers to become upright
walkers required a major recognisation of the muscular and skeletal systems
from ancestors that walked on all fours.
[via:Science daily]
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