It obviously doesn't ACTUALLY make you run faster. If it did, you would see it in the Olympics.
Any additional aerodynamics isn't made up for by the loss of swinging momentum of the arms and the awkwardness that causes.
There is a reason people swing their arms when they walk/run, even though it uses significantly more energy to do so.
Indeed, I thought perhaps the reason you would see this run is that maybe it used less energy and helped for distance, but that is unlikely too, because it is probably more work to keep balance overall---and there are people who can basically run so long that what they have to stop for is sleep anyway.