OK so I'm on the brawn push over the next few months... especially given how sore my legs were after skiing the other day. I can leg press pretty big weights but it seems that my legs still got realy sore skiing so I think the problem is in my stabilisers not being strong enough. What's everybody doing for lower body stabiliser work?

I can just manage 1/2 a dozen Swiss Ball squats but that's a fairly perilous exercise to do Tried doing one legged medicine ball squats today but too unco-ordinated. Anyone have any ideas? Suggestions?