Em MacIntosh
3rd Black Belt
I would vouch for doing a little wrestling and boxing though as well. Just the basics of both. Karate isn't really know for it's groundfighting (can't speak for TKD...) so it's good to roll around on the mat a bit, so if you do happen to go down, you're in familiar territory. Boxing might help you loosen up your karate, something I still have trouble with. It's good to practice rolling with the punches, taking a hit, bobbing and weaving. Great for footwork too. If you want to stick with a more traditional aproach, jiu jitsu and karate or judo and karate go together like flies on rice. You might be able to ask your sensei to teach you some karate groundfighting that I've never heard of though. Bring your concerns about your art's perceived weaknesses to you sensei's attention (respectfully and tactfully) andhear his/her opinion. Don't try to disprove your sensei though. It's more like asking an expert. He/she might be able to reccommend another art to supplement those possible weaknesses.