When trotting stirrupless (usually sitting) on bouncy horses, I have real problems staying in the saddle. I tend to slip to the sides and my legs and hips tense and ride up. I make conscious efforts to loosen my hips and sit back a tad, but I'm finding it quite difficult anyway - no chance of cantering just yet, I'm positive I would fall off.
When trotting with stirrups, I'm fine, but on those really bouncy horses I have problems getting into canter because I find it hard to sit, and I feel like I'm confusing the heck out of the poor creature!
Thankyou for any input, this is really starting to frustrate me, as I'm not going to be riding perfectly smooth horses all the time (unfortunately).