My young horse is quite sharp and gets flustered when I have to use a stronger aid for things. When she distracted the canter trans aid has to be a little stronger than normal which then upsets the whole canter. She will leg yield/ shoulder in quite nicely in walk and trot but mostly from my seat. If I do use my legs she tends to either become hot of almost push against them. My other issue is that she can rear when faced with something scary/something she doesn't want to do. I find it hard to keep her infront of my leg without making her crazy. If I let her keep ticking along underneath me she is beautiful and light in the contact and will stretch and come back up onto the bit no probelm. If I use my legs too much for her liking she contact is very inconsistent, she snatches, shakes her head and becomes very heavy particularly to the left. Back/saddle/teeth feet all fine. Fed a high fibre low starch diet and is on an ulcer treatment program to see if that helps.