Beleive it or not, sway starts with the knees. Although sometimes we say "hips", you shouldn't take that literally because to disengage the hips is to move your body in isolated pieces, as in Latin. That's not good. "Hip" sway is actually caused by the action through the knees and ankles.
Sway of the upper body is simply a lengthening or stretching upward of one side or the other. Often there's an element of rotation of the rib cage so as to project the lengthened side through an angle upward and forward (or upward and back).
The best way I know of to correct problems with upper body sway is to manipulate with hands. Literally grab your ribcage on either side with your hands and pull one side up. Pay attention to the lengthening through that one side, but more importantly, monitor the non-lengthened side. Make sure that it is not actually shortening.
This should be fairly easy to do as an exercise, targeting only upper body sway. The problem is that most of the time when dancing, you incorporate both upper and lower body sway at the same time. Until you train it correctly, the body will have a tendency to do everything together. Just like a pianist has to train his right and left hands to do different things at the same time, when learning sway you have to train your upper body how to stretch upward, especially on the low side. There is a natural tendency for the upper body to "crunch" rather than stretch on the low side, in an attempt to aid in or increase the sway. Your job is to negate this natural tendency.
Once again, I find that hands often do the trick. While incororating lower body sway, place your hands at your sides in such a way that on each side, your middle fingertip is pressed against the top of your hip bone, and your hand is stretched with your thumb prssed against your side, almost to your armpit (or as far up as it can go). You'll notice when one side of your body shortens because the hand begins to close like a claw. Keep the hands in that position and dance through some box steps (or whatever actions give you sway trouble). Make sure that you're incorporating lower body sway. While doing so, monitor the upper body sway with your hands. You'll feel the natural tendency of the low side to want to crunch. Use your hands to prevent it from doing so, and even to encourage it upward. A good key phrase I use with my students is "low side long". Keep that in mind as you dance.
As for trouble with rightward sway / leftward head, once again, use your hands. I call this one the "Victor" (after Victor Veyrasset, who taught it to me): Take your index and middle fingertips and press them against your right temple in order to fix your head into its leftward position. Sway left, and it's no probelm. Sway right, and you'll find the fingers very helpful. Now maintain a rightward sway, let the fingers go, and see if you can maintain your head in that position without them. This is the position you will ultimately want to achieve while dancing. But as long as you have trouble maintaining it, keep using your hands, or better yet, have your teacher or partner do the Victor for you. It's very helpful.
Regards,
Jonathan Atkinson
www.ballroomdancers.com
When I try to move only hip, then I feel cranch my left side. That's not sway....then I try to streach, then my head moves. Anybody had similer problem and fixed now? I am practicing a lot, but feel tired about this........