Yao Ming and the froghopper Just a few days after a tough and
inspiring performance against the Lakers, Yao Ming is injured
again, with a stress fracture in his foot. Lakers coach Phil
Jackson commented on Yao’s fragility by saying “A person in
physics once told me if man was 60 feet tall, the first step
he’d take, he’d completely crumble … Gravity’s a bitch.” But is
it true? Certainly larger people have heavier bodies, but they
also have thicker bones and larger muscles. So why are tall
people more prone to injury? This post examines that question
using one of the simplest and most powerful ideas in physics:
the scaling argument. I will also try to make a prediction for
the “injury prone-ness” of a person as a function of their
height. Before I get to Yao Ming, allow me to discuss a simple
example using what is arguably the best athlete in the animal
kingdom: the froghopper. The froghopper is a little insect,
barely half a centimeter long, but it has about a 27″ vertical
jump. That’s about 140 times its own