no, really, it's a football question

After giving thanks for bounteous blessings and a departed life well-lived, we sat around postprandially and snoozed, or, perforce, watched a little football. I noticed that, at least for the part of the game that I saw, before most of the plays in which he participated, Alex Smith, standing behind his crouched linemen, would extend his arms in front of him, elbows bent, and roll his forearms over each other a few times. What did that mean? I asked the football mavens in the household and they didn't know.