A recent study by team of three biomedical researchers from the USA and Holland (headed by Steven Collins at the University of Michigan) has, according to all the newspaper articles I ran across, solved the “burning mystery” why people tend to swing their arms asynchronously with their legs while walking. Apparently, these researchers have managed to put a figure on the energy savings that are involved. The study says that it takes 12% MORE energy for the muscles to keep one’s arms straight by one’s side versus letting them flow freely. The force of a walker’s contact with the ground increases by 63% if the arms are not moving. All in all, rather credible stuff.
I must admit that my attention was originally grabbed because of the “energy savings” (i.e. green) principle bandied about in the press headlines. But, in the first place, it turns about to be more about energy efficiency. And, from a health perspective, we end up saving only the calories we do not burn — which, for so many of the less active people, is NOT a good thing.
Meanwhile, I cannot imagine justifying the resources that were allocated to do this study! I saw no good explanation of any greater societal benefit from this research. A mystery solved, perhaps, but not one that kept me awake at night. As an alternative, I might have suggested asking Usain Bolt to try running the 100 metres without using his arms.