Tuesday, 8 June 2010

Touch and Go #8

Posted by speedygeoff on Tuesday, June 08, 2010 with
What causes heel strike?
“A major factor contributing to the predominance of RFS landings in shod runners is the cushioned sole of most modern running shoes, which is thickest below the heel, orienting the sole of the foot so as to have about 5u less dorsiflexion than does the sole of the shoe, and allowing a runner to RFS comfortably. Thus, RFS runners who dorsiflex the ankle at impact have shoe soles that are more dorsiflexed relative to the ground, and FFS runners who plantarflex the ankle at impact have shoe soles that are flatter (less plantarflexed) relative to the ground, even when knee and ankle angles are not different.”

Evolution:
“Differences between RFS and FFS running make sense from an evolutionary perspective. If endurance running was an important behaviour before the invention of modern shoes, then natural selection is expected to have operated to lower the risk of injury and discomfort when barefoot or in minimal footwear.”

This essentially means, we’ve got millions of years of adjustment and fine tuning that went on to allow us to run barefoot with minimal risk. In addition, Lieberman points out several evolutionary changes that aid running. The development of the arch, which is essential for elastic energy return, is one of them.

from Science of Running by Steve Magness. To be continued...

Bob