Have you ever considered why it is that you swing your arms back and forth and in the opposite direction to your legs when you walk? Well wonder no more, as a group of scientists have come up with the answer – it helps to make your walking simpler and more effective.
Scientists have been trying for years to unearth the reason behind this seemingly pointless arm movement, with some believing it was an evolutionary reflex from the times when man walked on all fours.
However researchers from the US University of Michigan and Delft University of Technology in the Netherlands could take the mystery no longer, making it their mission to find out why those arms swing when they do.
So, they went about constructing a mechanical model in order to get an overview of the logistics of arm-swinging, as well finding 10 volunteers who were asked to walk with a normal swing, with their arms tied at their sides or held there, and with arms swinging in time with each leg.
As a result the researchers discovered it takes 12 per cent more metabolic energy to hold the arms still during walking compared to them swinging away.
In addition, they established that it takes the body 26 per cent more energy to get the right arm to move with the right leg and the left with the left – the opposite of what we naturally do. The results were published on Wednesday in Proceedings of the Royal Society B, the biological research journal of the Royal Society.
In addition it was found that by swinging the arms, the movement of twisting or “torque” of the body, was counteracted – making it easier and smoother for the body and legs to walk straight – using less energy from the muscles.
“Although arm swinging is relatively easy to achieve, its effect on energy use during gait is significant,” the researchers wrote in their report.
“Rather than a facultative relic of the locomotion needs of our quadrupedal ancestors, arm swinging is an integral part of the energy economy of human gait.”
So there you go, now you know - we swing to make things easier – sounds like human beings doesn’t it?
