BUTT some of our gluteus muscles concentrically contract to create movement while we are executing some of our steps. These are the gluteus medius and gluteus minimus. It's nearly impossibly to isometrically contract these muscles (contract without moving them) so the concept of keeping the glutes relaxed is totally correct and valid. But technically some of them will contract naturally to create movement. It's important to think about these as natural contractions. We don't want to actively think about contracting them because then we'll only end up contracting the gluteus maximus and we definitely don't want that.
Just to be sure we are totally clear. Look at the image below.
Contract only your gluteus maximus. Easy right? Now relax them.
Contract only your gluteus minimus. How'd it go? How about only your gluteus medius?
Now you get my point?
To feel abduction: Stand up tall and take your right leg out to the side. Tadaaa....abduction.
To feel internal rotation: point your toes inward.
You can even do both at the same time :)
If you find that after a long class of hip bumps you are feeling some muscle fatigue on the outside of your hip. You are probably feeling your gluteus medius and minimus! This is a sign to check in with your feet! If your right foot is out farther than it needs to be, then you are abducting (leg away from your body). When you add a hip bump on top of this abduction...of course you are going to feel the burn!
For a hip/pivot bump, your feet should be comfortably together. Most weight in your left leg. Both legs are active, but the left is more weight bearing giving the right leg some freedom to move.
Hip Bump Feet Example
If you are one of those people that feel you need to "balance out the left" after dance, then here's a little exercise you can do before heading home after class.
Single leg lifts (do 10-15 of these, rest and repeat). Be sure to keep your spine long. No duck butts!
Keep them small to ensure you are using the muscles and not the momentum.
If you have any questions please feel free to contact me firstname.lastname@example.org