Drew this cartoon for the Q & A for TINKLE october 2009 issue.
Q: Why do we swing our arms while walking?
A: In experiments with robots and human volunteers it was found that when the arms swing naturally, the effort put in walking is 10 to 12 per cent less than when the arms are kept steady at the side.
So the arms swing to minimize effort of walking.
lol. it is difficult to walk without swinging arms
only option is to keep them in pant pockets.