Besides a mildly humorous premise, When you take a look around the US and how we live and eat... This is true... but its not just White Men... Id say, Americans Can't Jump. Sure we have outliers. but by the time we are in our 30's if we aren't actively participating in sports or specifically training to jump... we just arent able to anymore... our kids don't seem to have a problem.. relative to their size of course.
Craig Weller from T-Nation did a great Article about the Third World Squat. I think its a great read about Sitting, Squatting and what we've forgotten how to do, here in America.
http://www.tmuscle.com/readArticle.do;jsessionid=931E7C67CC4D68CDD14935F00ADDDD39.hydra?id=1856085
The classic North American squatting down to grab something from a low shelf or play with his VCR is going to balance on his toes and shoot his knees forward. He's going to try and make the movement feel as much as possible like his natural environment, which is sitting in an office chair.
Home to many butts.The hips and ankles are immobilized and because the force is being relegated mainly to the quads, the effect of the posterior chain is minimized. The musculature of the lower back will be overactive in order to support the weight of the upper body without much assistance from the glutes. The thoracic spine will generally be flexed forward into a kyphotic posture.
Our Swahili-speaking friend is going to keep his weight on his heels. His feet approximately shoulder width apart and pointed straight forward, with maybe a small amount of external rotation. His feet are in line with his knees, and he'll squat down placing his kneecaps neatly into his armpits. This isn't a skill that he acquired at some point, but simply one that he never lost due to a lifetime of immobility and office work.
An advanced trainee.
In this posture, the thoracic spine is neutral and can be easily extended depending on where the individual's attention is directed. The hips and ankles are able to move freely and remain mobile. The posterior chain is carrying the weight of the body, rather than the quads. When he stands, the power to do so will be generated through the glutes and hamstrings. The lumbar spine remains stable and is used primarily to transfer, rather than generate, force.
