Jim makes a good point in moving off the GL to sell your short call. I just added that point to our wing breakout session in our clinic this August.
As for making a call on your butt, it reminds of when I was doing a game as WH on a wet field. There was an interception and I had to get to the GL. On my last stride to the GL my foot slipped and I ended up making the TD signal from my knees. All in all, I thought I had pretty good form and I was expecting the FED to add that signal as an alternative signal the next year.
