Article continues below advertisementMichelle Obama demonstrated her quick thinking and compassion on the tennis court at Martha's Vineyard recently when she sprang into action to help an injured player.Disaster struck as two men, one of whom is NYC restauranteur David Rabin, played on a neighboring court to the former First Lady, according to a report. During the match, one player dove to chase a lob and fell, tearing his hamstring in the process."It's like he's showing off for Michelle Obama and he trips!" a witness shared. "He's lying on the ground...