SACH-SAWCH

To protect our talus in situations where unexpected excesses are likely [hiking], we wear constraints - boots - with firm ankle 'support'. Constraints cost energy as small deviations are now transmitted up the chain of support and not subtracted smoothly from the walking experience. It still beats fractures. We will see later why boots almost have to have heels. Heels a must? See if you can guess why as we later discuss prosthetics. In trying to fit segments of motion to normal relaxed walking on level ground, Inman described 6 “ determinants of gait ” [the things our parts do in harmony to conserve energy by traveling a low sine wave path from A to B. But beware of laboratory conclusions. They fit laboratory conditions – flat level surface. Our walking can adapt such that undulating ground barely changes the path of our body. This mechanism has inertial sensitivity.

That long horizontal scratch on your BMW? Did you actually not notice driving too close to some protruding object? Or was it 'keyed'? If it was a straight line scratch, then it was moving on wheels from A to B. If the scratch is a sine wave, then some moron, WALKING by, did it. The height of the moron can be calculated. The length of one full sine cycle is 75% of the moron's height. Got that, Dr. Watson?