How to keep straight legs in a cartwheel?

My cartwheels have improves a lot, I feel, and I get a lot more good reach and power out of them. Previously I had only ever seen myself cartwheel by looking through my arms into the mirrors as I did one, and they looked alright. But I filmed myself down the line of the cartwheel yesterday and to my surprise my legs are completely bent during the middle (inverted part) of the move. My knees are not quite 90 degrees but getting on for it, and it looks horrendous.

It really felt like they were straight - can anyone suggest how I can fix this? Any drills to teach me what straight legs actually feel like and how I can stop them flopping over like that?

I can post a video if it would really help but I suspect you know what I mean. I suspect my roundoff looks the same - which is really no good at all.

Thanks,

Had the same problem, you just need to really force yourself to point your toes and tighten your legs.

Agreed, point your toes

Having a good standing scale helps immensely.

 sit in a straddle. point your toes so hard your quad tightens up.

 I once shown a neat drill for straight knees on pommel horse for the little guys:

 Attach something plastic underneath the knees. Tape it down. Each point should roughly be the lower part of the hamstring and calf.

 If they bend their knees, Oww. It kinda jabs into their skin.

 I've used plastic straws instead but carry some nails or screws to scare the crap out of them...just in case.

Squeeze your butt really hard (and point your toes and all the other stuff people said). Squeezing your butt opens up your hips so you do not have a pike in your cartwheel. If you pike, your legs will bend and buckle right before you land. 

I have this same problem.You are not alone. Just saying,my gymnastic class teacher says pretend you don't have knees.