Designed for running August 18 2017, 0 Comments
We are designed to run, and a number of our design features passively help us to do so.
We've previously discussed the anatomical features that show how we have evolved as long-distance runners. Our long legs and impressively large buttocks give us a long, loping stride. Because we are bipedal, our stride does not limit our breathing in the same way as for four-legged animals. Our ability to sweat keeps us from overheating and enables us to outlast animals that can only cool themselves by panting. The nuchal ligament in our necks, which is not present in tree-dwelling apes, keeps our head stable while we run. And finally, strong elastic ligaments in our feet and achilles tendons store energy from our landing and re-use it in the push off into the next stride.
Professor Dan Lieberman eloquently explains and quantifies the passive elements of running in this short video, explaining that the arch of the foot stores 17% of landing energy, and the achilles tendon another 35% - energy that does not have to be generated in the muscles to contribute to the next step as it is released naturally by the springy ligaments. There are two conditions for this to work at its best - we need to run and land with good form, and we need to relax while we run so that our passive mechanisms can make their contribution.
So, shoulders down, easy breathing and a light, springy step in order to enjoy the countryside around you rather than focusing on the effort - after all, if you are doing it right, 52% of that effort comes for free.