What type of gymnastics do you do with a horse that is super powerful in the hind and sort of uses that as a crutch to just throw her front legs out in front of her? She is a little but of a worrier - I do basic gymnastics with her but once she settles into it - she still is powering off her rear.
I have a mare that has a tremendous amount of power, but is very unpolished at the moment and uses her power to get herself over the fences. This isn't a problem with the courses at shows at the moment, sicne she's only a 5 year old, but once the courses get more technical and triples are introduced, this will become an issue.
To work on this I've set up in my jumping field alternating height bounces as well as a grid: x, placement pole, vertical, placement pole, oxer with v poles.
The placement poles help her regulate the canter in between the fences and help keep her from "worrying" and the v rails (which I started out quite wide and narrowed them to an apex once she was confident) back her away from the front rail as well as keep her front legs tight over the fence.
The alternating bounces, I enter at a very collected canter and allow her through them and the alternating heights make her think and naturally back herself off rather than just power through.
I like bounces with tall crossrails... make sure you squish in the standards when you make it tall so its a little bit narrow... I've had good luck with that one... one strides too... 18' all the way thru.