I thought I had seen this video a long time back , asking for a critique. Did you post it before?
Anyway, I agree with Delete in that you are "pumping" in the saddle and this is annoying the horse. He is holding himself back and moving in a protective, stilted manner. You are moving too much forward and back, which end up being that your timing for going down into the saddle is a milisecond late, and you are bumping down when he is already coming up. He is moving too much up and down because he is kind of rigid and humping a bit . I think his annoyance is eveident in his swishing tail.
Another person said to kind of glue your seat to the saddle. Of course, no one can "glue" their seat to the saddle. But, you need to have enough adherence to be able to find and match his rythm and not be that milisecond behind it.
So, think of having adherence from your seat bone/crotch area, down to the inside of you knee. Your lower leg is just hanging there. If it weren't for the stirrup, it would fall on the ground.
To feel adherence, you create "tone" in your leg. Not a severe grip in the knee, but the whole fork of your seat from crotch to knee , will apply a bit of pressure to the saddle, just enough so that when the horse walks (do this first at the walk) there is NO rolling of your thigh with the motion. Your thigh doesn't roll because it is part of the saddle and move for and aft, side to side, in exactly the same motion and speed as the saddle. Yes, there is some tightness in the leg, but not a death grip. and, remind yourself to not squeeze you anus closed . Forgive me for using such a crude term, but if you squeeze your anus closed you will be tightening your butt muslces, too, and in so doing raise your seatbones off the saddle. NO! you want the thighs to be toned, ON the saddle and moving with the motion, butt cheeks relaxed and loose. IT CAN be done, I promise you.
AS you ride at the walk, think about the top/front of your thigh as kind of "leading". Focus for a bit on the joint where you thigh meets your pelvis, on the place that is kind of at the very forwardmost place. There's a big tendon that is used to draw the leg against the horse. YOu should feel that this tendon is engaged. Feel it with your hand down there (kind of crotch area, so folks might get wierd ideas, but do it). Now, as you feel that thigh and that joint, let THEM follow the motion NOT your waist. Your hips are the thing that bends, openning and closing, to follow the motion, NOT your waist. YOU stay as upright as a tree is on a hillside; it doesn't matter how steep the mountaing, the tree is always vertical.
Please try this and let me know how it goes.
ETA The tendon is the one you will feel if when standing up , you lift your leg upward, not inward.
Last edited by tinyliny; 01-12-2013 at 12:03 PM.