Thursday, March 20, 2008

Walk like an Egyptian a typical biped Upright Walking Began 6 Million Years Ago
A shape comparison of the most complete fossil femur (thigh bone) of one of the earliest known pre-humans, or hominins, with the femora of living apes, modern humans and other fossils, indicates the earliest form of bipedalism occurred at least six million years ago and persisted for at least four million years. William Jungers, Ph.D., of Stony Brook University, and Brian Richmond, Ph.D., of George Washington University, say their finding indicates that the fossil belongs to very early human ancestors, and that upright walking is one of the first human characteristics to appear in our lineage, right after the split between human and chimpanzee lineages. Their findings are published in the March 21 issue of the journal Science.

UPDATE: Speaking of upright walking. . . .the reason for no posting yesterday was a result of me going to a physical therapist for, yes, lower back problems!

Had 'em for years. My lower back (spinous erector) muscles would spasm a lot. Talk about pain. It's been on and off for years, which I thought was due to the weight room. In my misspent youth I used to squat 350 pounds, which I kind of thought might have had something to do with it. I gave up squatting a while ago, but the ol' back went out again a few weeks ago and finally decided to see a sports medicine guy about it. He diagnosed a problem with my shoulder a while back and the PT fixed that up nicely, so I thought it was time to give him a go at the back.

He (the doctor) said it was probably a disk, but the PT Guy said it was more like just the muscles due to, um, horrible posture and such. So he spent an hour torturing me and now I've got some exercises to do to strengthen my lower back and general hip area muscles. And correct my posture. I can tell those muscles are weak because they've been sore ever since. Not spasm-sore, just basic soreness.

I've thought for a while the whole bipedalism issue is what is responsible for the raft of lower back problems people have, but now I'm starting to rethink that. Maybe. The thinking goes that the lumbar curve is somewhat "unnatural" due to causing the spine to go upright from a (probable) quadrupedal ancestor. Trouble is twofold: First, the PT guy indicated that one is supposed to maintain that lumbar curve to avoid back difficulties; exactly the way it's supposed to curve. What causes the problems is sitting and standing wrong and pushing the curve backwards -- straightening it out, so to speak. That suggests to me that we're okay with the curve, but more "modern" (see below) living has screwed up our natural and back-appropriate posture.

What's "modern"? That's the second fly in the ointment. On the one hand, I'm not clear to what extent past peoples had lower back problems. One would have to review the literature on skeletal abnormalities going back in time. I have memory tickles of various arthritic vertebrae on older skeletal material, especially those involved in the Giza pyramid complex. Did Pleistocene hunter-gatherers suffer similar conditions? Would enough of them have lived long enough to have developed symptoms that would express on skeletal remains? So there's my next research project.

Other than that I'll just sit around complaining about my achin' back. . . .