I have just finished reading a book about the way we walk - 'Born to Walk' by James Earls. It is really aimed at physiotherapists and movement therapists and as such assumes a knowledge of anatomy that I don't have but as long as you don't try to follow every detail, it is still very enlightening. It has really opened my eyes to how efficiently we walk.
The book talks a lot about the fascial tissue which forms a thin casing around every organ, blood vessel, bone, nerve fibre and muscle in our bodies. Fascia has its own nerves and tightens up when it is stressed.
Humans have evolved a very economical way of walking on two legs where we 'vault' over our feet and reuse the energy that comes back from the ground when we put our feet down. Rather than contract and relax our muscles with every step, we use tendons and fascial tissue as springs with the muscles just being responsible for adding a bit of energy and correcting our stance every so often. Of course, more effort is needed by our muscles if we walk up or downhill.
This explains why walking around a museum or shopping centre can be so tiring. Instead of getting into a rhythmic pace, we are continually stopping and starting and wasting the momentum of the previous step.
Because walking involves bending and twisting, we counter this by using our whole body and our arms both to maintain balance and also as further energy stores to be released on the next stride.
By evolving these mechanisms our species found a way to wander over a large area searching for food with minimal use of calories.
Each step includes a number of 'key events' that allow us to use the foot as a rocker. The heel strikes the ground and then we flex the leg so that the energy is absorbed into the ankle, knee and hip as we roll over the ankle and then forefoot. As our full weight is taken by the foot the bones in the foot spread out before reforming into a dome as we push off on our toes and start the next step.
If any part of us is injured or stops functioning properly we can compensate by using our muscles but this results in a loss of efficiency and puts stress on the rest of the system.
We have different mechanisms for walking, running and sprinting, just as horses walk, trot, canter and gallop. The faster we go the more we use our arms to counter the rotation caused by our legs so that we keep our head and eyes as stable as possible.
Moving on from the book, another fascinating topic is Gait Recognition. The Chinese company Watrix is developing machine learning software that can identify people by the way they walk. Developers currently claim 94% accuracy. Scientists at Manchester University claim almost 100% accuracy for their AI software that analyses the way you put your foot down on a pressure pad.
The funding for the work comes from companies who are interested in using it for security purposes - at airports for example, but it is also claimed that it can help to detect the onset of mental illnes.
Just like fingerprint recognition, the systems rely on having a pre-existing database of people and their gait.
This link between walking and mental health is important. Personally I love the feeling of being 'in the zone' you get when you are walking at a comfortable pace and rhythm and it is a form of exercise that is available to most people.
