Flour Sack: "You're tripping"

This animation is my greatest failure in this class, nay in my life. The sacks look inappropriate at best, with bulging buttocks. I wanted to make the one sack trip the other sack and then laugh at him, but it looks as if they are twitching and undulating in convulsions. The walk is ALL wrong. I wish I could burn this. I plan to remake the flour sack exercise COMPLETELY. Lets just forget it, people. I was truly TRIPPING when I made this. ;D