Recently I saw a video of myself doing kata (for karate) and I looked as though I were just gliding along. I am not sure of the correct terminology, but I know this is because I am not using my muscles, simply just putting my limbs in the correct position.
When I do use (flex??) my muscles, I become rather tense and rigid rather than strong. How do I stop this? How can I have a strong stance and technique without being tense and rigid?