Why We Walk on Our Heels Instead of Our Toes Walking heel-to-toe gives humans the mechanical advantage of longer "virtual limbs," suggests UA researcher James Webber. Alexis Blue University Communications Dec. 12, 2016 https://uanews.arizona.edu/story/why-we-walk-our-heels-instead-our-toes
I tend to see 7-8" as a pretty frequent internet size. That's like a guy thinking well I gotta make myself look better but I don't want to be completely outrageous.. 7.5" it'll be.
it's usually 8.5 inches. almost every masturbating basement dweller picks exactly 8.5 as his internet penis length, like they all had a meeting and decided that was the maximum believable size.
Free pdf of research paper. The role of plantigrady and heel-strike in the mechanics and energetics of human walking with implications for the evolution of the human foot James T. Webber, David A. Raichlen Journal of Experimental Biology 2016 219: 3729-3737; doi: 10.1242/jeb.138610 http://jeb.biologists.org/content/219/23/3729
But it doesn't explain why animals such as dogs and cats walk on their toes. Why didn't humans develop the same strategy?
Modern human feet seem to be optimal for standing stable, walking long distances with minimial energy, and running fast. People do all of this with only two feet that evolved from primates with hand-like feet. Standing on two legs requires a large enough ground contact area to be stable for a body with a high center of mass, which explains why people stand with all area of the soles in contact with the ground (plantigrade) as opposed to standing on the toes (digitigrade). Compare this with an animal that walks digitigrade but has four legs for much more stability and doesn't need a large foot area contacting the ground for standing or walking. Walking turns out to be efficient for people because of the effective increase in leg length due to the heel-toe stride and elastic nature of the foot, something that wouldn't be as efficient for a two-legged human walking on toes (as the research paper stated). Human barefoot running is often done on the forefoot (ball and toes) and is efficient and fast. Much longer feet probably wouldn't be optimal for walking and running and shorter feet wouldn't be stable for standing on two legs. Overall, the human foot is optimal for all three of these activities which likely gave early people a survival advantage. There is also the pragmatic issue that people evolved from primates and inherited a particular leg and foot morphology. A lifeform has to take what nature has given it at the time and modify it within certain constraints in response to environmental pressures. The morphology probably couldn't change very greatly over a couple million years, such as primate legs evolving into those very similar to those of a cat or dog. Modest changes happened over time, such as the big toe becoming parallel with the other toes and a pronounced ball and heel developing. The human foot has a mild resemblance to that of an animal that walks digitigrade to the extent that it is like a lever that permits one to stand or run on the toes if desired. It's not to the extent of a four-legged animal like a cat where the digitigrade form is much more pronounced and used all the time, and it probably won't become like that because overall it would likely hamper the locomotion of a two-legged human more than it would help it.
