I used to go riding for a few years then a had a break and now I'm coming back to it. They used to put me on easier horses before but now that I'm older they are putting me and harder horses and I'm finding it really hard to get them into canter. My instructor said its to do with my leg positioning - that it needs to be further back behind the girth. I try to put my leg back but its hard to squeeze the horse like that. So when I come up to a corner in trot and do sitting trot I try to put my leg back and squeeze but it seems to goes really quick and I feel in a really bad position when I'm trying to squeeze the horse into canter - it feels like my body goes forward when my leg goes back.
Is there any advice in how I can get the horse to canter? Am I doing it wrong?