I didn't go to any classes this week, but I did some private training yesterday. During this time I had someone hold a kick shield for me and I was practising round house kicks -- I practised both the way I was taught in GKR with the knee sticking out, and the way I was taught in Tai Chi with the knee up front. Aside from the groin-defence issue, something else that I didn't think about before came up -- power. I found that the knee up front roundhouse kick delivered greater power whereas the knee to the side delivered noticeably less power.

The immediate explanation that comes to mind is less rotation, which of course means less rotational energy. When sticking the knee out to the side, my leg is already positioned for a roundhouse kick, so the leg just swings in. My supporting leg and hips do rotate, but my kicking leg does not. Whereas with the knee up front version, the kicking leg needs to rotate 90 degrees as the kick is delivered. This extra rotation would naturally generate additional rotational energy.

I actually wasn't even looking to compare the power output of these kicks, I was practising roundhouse kicks and I just felt like practising both versions... I mean, I've been practising all these new punches and kicks in GKR class, but never had the opportunity to try them with any form of tacticle contact, so I decided to see what it would feel like to deliver a roundhouse kick as I've been taught in GKR. To my surprise it was quite weak -- and I wasn't trying to be weak with it, I delivered both roundhouse kicks with equal strength. I could feel that the knee up front version was stronger, and the person holding the shield said so too.