Re: A Woman's Center
Lots of food for thought here --
First off, I was surprised at how people took Jon's suggestion. I'm an engineer, and knowing a few seriously topheavy women I found myself thinking that in some cases (not enough to generalize to all women) that probably could raise their center of mass by a non-negligible 5% or more.
I tie my belt at my waist because that's where it stays put.
My center of mass is most assuredly below my waist, probably about three fingerwidths.
I was recently training at a karate dojo that shares space with a ballet school, and there's some cross-pollination. The karate instructor mentioned that all the dancers had trouble lowering their centers when they started, because in dance they are taught to float.
Re Sunny's observation on having a baby: I'd had mine over a decade before discovering martial arts, so maybe it's just that I'm used to them -- but I'm able to find my center (spiritual as well as physical) just fine. I go to class thinking about a zillion different things about work and family, then let it all go as I prepare for class and get filled with aikido.
As for John's question re differences in techniques, I have a feeling it's my relative shortness that's the biggest cause of any differences. I'm close to a foot shorter than nearly everyone and weigh about half what some of my classmates weigh. Many of them have trouble sinking their centers under mine since they're so much taller; but if they do manage it, I go flying. I'm more agile than the big, muscular guys, but I figure that's because I'm so much less massive so I have much less inertia (please forgive the engineer talk again; I can't help it, it's how I think). I know I'll get better at it as I study longer, but I haven't yet mastered the subtleties that'll let me overcome the basic physics -- if I don't get out of the way, I can be launched really easily by bigger people even when I feel well rooted. Again, though, I'm sure that's because of my size not because I'm female with a slightly lower center than a comparably sized male.