Emergence and optimization of upright posture among hominiform hominoids...

[bernard]

Neurosurg Focus. 2007;23(1):E4.
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Emergence and optimization of upright posture among hominiform hominoids and the evolutionary pathophysiology of back pain.

Filler AG.

Institute for Spinal Disorders, Cedars-Sinai Medical Center, Los Angeles, California, USA. afiller@nervemed.com

The lordotic region of the lumbar spine is a significant focus of pain and dysfunction in the human body, and its susceptibility to disorders may reflect its substantial reconfiguration during the course of human evolution. The basic anatomy of the lumbar vertebra in Old World Monkeys and Early Miocene apes, or proconsulids, retains typical mammalian architecture. The lumbar vertebra in humans is different in the repositioning of the lumbar transverse process dorsal to the vertebral body rather than originating on the body itself and in the loss of the styloid process that is adjacent to the facets in other primates. These two features appeared in Morotopithecus bishopi 21.6 million years ago, suggesting that this ape is the founder of an upright hominiform lineage. The iliocostalis lumborum muscles migrated onto the iliac crest approximately 18 million years ago, becoming a powerful lateral flexor muscle of the trunk. The posterior superior iliac spine shifted far dorsal to the longissimus insertion in the genus Homo between 1 and 2 million years ago, making this muscle a powerful extensor of the lumbar spine. Functionally, the establishment of strong muscular flexors and extensors adds dynamic compressive stresses to the lumbar disks and also makes these muscles susceptible to strain.

Publication Types:

• Research Support, N.I.H., Extramural

PMID: 17961059 [PubMed - in process]

[Diane]

The big brain came later - did the big brain make back pain worse or better? My hunch is, likely worse.

I see they are perpetuating in this article the idea that pain comes from back muscles and joints instead of from brains and nervous systems.

[bernard]

A big brain is not really necessary but another lecture is possible:

Man inherited a beautiful, marvelous and strong back but it is like a Ferrari, you need to learn how to drive/pilot it. In the contrary, you have to pay for repairs but it never learn you to be a champion.

[pht3k]

Originally Posted by bernard

Man inherited a beautiful, marvelous and strong back.

i have been told in a course that our back is not that strong. here the explanation:

we come from the apes. before the apes we were animals walking on 4 members. the evolution made the spine stonger for this activity. one day, the ape decided to walk on 2 members. there were no in-between. we walked much longer on 4 members than on 2.

walking on 4 members include: no gravity compressing the spine. and mostly extension movements, to climb a tree, to jump on an other animal, etc... almost no flexion. so the disks are sollicitated mostly in the anterior wall. so the anterior wall became stronger.

since the evolution from 4 to 2 members have been too fast for evolution, the spine is still stronger in the anterior wall than the posterior. but we now do flexion, sollicitating the posterior wall. this is probably one of the reason why there is so much disk lesions, symptomatic or not and why almost all disk lesions are in the post wall.

pht3k

[bernard]

Originally Posted by pht3k

we come from the apes.

Not sure at all. Apes are apes and quadrupedal primates.
We are bipedal at birth.

Try to run on four, like apes.

[nari]

Hi pht3k,

Watch a movie/video of apes in action. They spend a great deal of time in flexion - grooming, observing, eating on the ground.
I'm not sure that we can blame our propensity for disc lesions on being bipedal...

Nari

[Jon Newman]

Any chance of getting the full text in SoS? I'm quite interested to read how they leaped from strong muscles to frequent pain experiences. It is implied that dynamic compressive forces to disks and muscular strain=pain in the abstract but I'd like to see if they expand on it any further in the article itself.

[bernard]

Jon,

Here is the site of the author =>
http://www.nervemed.com/

Do you really want that we give some money to this guy.

[bernard]

But I found it was a free access paper.