During the Five Golden Coins, and again as the second move of Eight Pieces of Silk, there are variations of the same maneuver, called Bend the Bow (but in Eight Pieces of Silk it’s called Bend the Bow to Catch the Hawk). In both moves, a lot of the energy of the maneuver comes from turning from the lower spine to generate the force of the motion, and coil up energy for use later.
About a third of the way through the first set, during Five Golden Coins, I realized “hey, I’m generating this turn/twist from my thighs. But it’s supposed to be above my waist, at the level of my hips or some such. If I generate this twist from my thighs, I can’t do Horse Stance below the waist. So where is this turn supposed to be coming from?”
It took me a couple of minutes to sort it out, but clearly, from above the hips in the flank muscles that run along the sides of one’s rib cage. I don’t have visible muscles there at all; I can sort of feel them, but it’s by no means a certain thing. Anyway, I started generating the movements of Bend the Bow from there, and the same when I got to Eight Pieces of Silk.
OW. Ok, but it’s the good kind of ow. And you know what else? There’s a certain satisfaction that when people say, “today I worked muscles I didn’t know I had…” after a particularly tough workout… I can say, “hey, I’ve done that.”