I just got back into my routine this week since my job is starting to settle down. I got on the stability ball and I am not sure if my form is right for crunches. I felt like I was laying with my stomach lower than my knees and when I did the crunches my lower back got a twinge in it. Should I go to the bigger stability ball? I guess I am thinking the knees should not be higher? Maybe my butt is to close to the edge?

Any suggestions would be great.

Darlene - when you sit on the ball with your knees bent, they should be at a 90 degree angle with your feet on the floor. Walk your feet out until you're lying back on the ball - the ball is supporting the small of your back. Your whole body should be in a straight line at that point - shoulders, hips and knees. Then you crunch. Here's a little video demonstration from Exrx.net (though his butt is sagging down more than I like): Ball Crunch .

If your stomach is lower than your knees, it sounds like your ball is too small. Here's some info on ball sizing: Determining the Appropriate Ball Size

Hope that helps!

Meg covered it all. I simply wanted to add that if you have a cat, make sure they don't try to climb on it.

You mean ... like this?

Exactly.

Although mine was more of a kitten and he more or less climbed up. Dug his little claws right in there. I could have stopped it, but it was a kitten on a stability ball... I mean, that's uber cute!

Wow Meg - your cat has great core stability!

OMG that cat is adorable there!

I wonder if I can get my pug to do that!

Heather - that's actually DD's cat and he's on the ball, talking to his bird friends out the window. He chitters at them and they chirp right back.