I'll put my two cents in: As a track/field/cross-country coach for 12 years, the theoretically correct way to hold your arms when running is with your elbows bent at 90o, and held somewhat close to the body. Your hands are to be relaxed so that you could carry a potato chip in them without breaking it. Your shoulders are also to be in a relaxed, normal position.
Now, with all that said, hold your arms in what ever position they feel comfortable. Just make sure that your neck and shoulders are relaxed, actually do shoulder rolls while running. And shake your arms out a little bit to keep them relaxed. But don't stress over it.
I been running for a long time and still can't keep my arms relaxed during some races, it usually happens when I'm really focused on my speed. I begin to tense up and up come the arms.
Oh so true, and probably right on target.
Great point.
I read this a long time ago and have done it myself often to keep my arms swinging right. Lightly tap your pinkie finger against the waistband on your shorts as you bring your arm back. Then for forward motion should be nearly straight out with some up and inward swing, but keep it to a minimum.
Another great point. Although I tap my thumbs.