How do I beat the last 2 test your might in Mortal Kombat?

I've been beating the test your might from the challenge tower with no problems up till the last two. The technique I used is to tap all 4 buttons with my thumb and first 3 fingers. Once the meter overshoots the mark, I hit the bumper button.

This technique is not working so well on the last 2 challenges. Are there any hints on how to beat them? I'm playing on the PS3.

I had to put the controller upside down on my coffee table, and use three fingers and a thumb and mash as quick as I could. Then used my knee to hit the trigger.

Yes, I'm serious...

Far easier is if you have a fight stick. You can happy hit all the buttons you need at once. I bought a fight stick for MK and the TYM challenges are a breeze.

I wait until the counter is at 4 or 5 (so I don't get sweaty) and vibrate my thumb (not too fast, otherwise it won't register) for 3 seconds. I try to get near the ring, and I speed up at the last second; the clock strikes for you and Bob's your uncle!