Why is it we move our hands whenever we are walking ?
I think it is all about stability , as kids, when we first decided to or rather felt we should walk , we struggled , we moved too fast , couldn’t control our movements and were wonderfully cute as we fell on our tiny butts. Then we started progressing , we realised how we can balance ourselves , how to put one step in front of another, and how to walk and run . In this process we ended up moving our hands so as to ensure that we could keep some stability , since as kids we have some asymmetry , the opposite hand movement coordinated with the leg is a great way to keep the centre of gravity where it needs to be . So we continued doing it and its the reason we see so many varieties of hand movement when people walk , each had their own individual way to stabilise themselves.