By Sean Carey

In his 1982 book Man, the Tottering Biped the South African-born anatomist and paleoanthropologist, Philip V Tobias (1925 – 2012), questioned the conventional wisdom, developed from Charles Darwin onwards, that standing in an upright stance on two feet freed our arms for tool making and tool using and marked a significant advance in human evolutionary history.

Tobias argued, instead, that the capacity to sit upright occurred long before the ability to stand on two feet and walk bipedally. Sitting upright, in his view, allowed our ancestors to develop a range of manual skills and with them the growth of a large brain.

Tobias made a further point about Homo sapiens’ achievement in standing upright:

“The way in which the body adjusted its structure and it bio-mechanics to the new way of uprightness and bipedalism may be described as little short of ingenious. Nonetheless, after perhaps four million years or more, we have not yet evolved a fault-free mechanism. Our bodies are still subject to what Sir Arthur Keith called the ills of uprightness. They include flat feet, slipped discs, hernias, prolapses and malposture. These maladies of uprightness account for much that keeps today’s orthopaedic surgeons busy. So the mechanism of man’s posture and gait, though resourceful and craftily contrived, is imperfect. The first human ancestors to come upright became heir to a host of new problems.”

That’s an impressive list but even so, it leaves out: plantar fasciitis, Achilles tendinitis, ankle sprains, shin splints, fallen pelvic floors, hernias, sway back (lordosis), a sideways curvature of the spine (scoliosis), a rounded upper back or hunch back (kyphosis), and spontaneously fractured vertebrae.

No one would disagree that standing upright, the head poised on top of the spine, is a truly remarkable achievement. Many biological anthropologists, such as Craig Stanford of the University of Southern California, believe it is the key defining feature of Homo sapiens. As he says in his 2003 book Upright:

“Of the more than two hundred species of primates on earth today, one is bipedal. Of more than 4000 species of mammals, one – the same one – is fully bipedal when walking (a few oddities such as kangaroo rats and meerkats stand bipedally for a few moments at a time). If we include thousands more kinds of animals – such as amphibians and reptiles – walking on two feet emerges as the most unlikely way to get around. Kangaroos and birds such as ostriches and penguins are bipedal – sort of. But they are built on an entirely different body plan, and are not, strictly speaking, relying only on their legs for transport.”

Only the human primate, then, is able to come to a truly upright stance with fully extended knees and hips, that is without the bent leg joints found amongst bonobos and chimpanzees, our nearest relatives, and has the capacity to remain in that attitude for a significant amount of time.

Nevertheless, Tobias’s perspective on the problems of uprightness has plenty of contemporary supporters. “The human vertebral column is unique in its sinusoidal curvatures that allow the upper body to balance over the hips,” anatomist and physical anthropologist Bruce Latimer of Case Western Reserve University recently argued at a meeting of the American Association for the Advancement of Science (AAAS). “Turning a spine originally adapted for a quadruped into one that is perpendicular to the ground has resulted in numerous problems that are unique to our species. If you take care of it, your spine will get you through to about 40 or 50. After that you are on your own.”  Continue reading “Can we really stand on our own two feet?” →