Obviously I didn't explain very well. I offer up a treat. I get the contact I need. I give her a good girl. We do it a couple times and start to phase out that treat so she is doing it only for the good girl and the contact alone. She is now letting me touch her to her back without any treats, but just a good girl. We have had much success with getting contact this way in the past. It's kind of like dog training where you offer a treat at first for good behaviour and slowly get to the point where it's a good pat or a good boy for that good behaviour. She does not expect food anymore for the things I ask of her like rubbing her neck and her back and chest, poll and forehead. She isn't pushy and I constantly demand respect from her. I fully trust my trainer and her experiences. This method has worked for years for us. I really shouldn't have called this trust issues, honestly, I should have called it comfort. Because that is what it is.
I'm sorry if you feel that how I am gaining that contact and getting her to relax is dangerous, but when I am in the field with my mare she is no longer tense but is relaxed and comfortable. Again, sorry for the use of the word trust. I obviously wasn't clear about this at all.
As Pat stated, it's more about desensitization than trust. She is sensitive to anyone touching her hind quarters and we're attempting to make sure she is no longer sensitive about this. I work for a long time on the small points, we'll move from the neck to the back and when I am out there just filling up waters or doing night check I'll stroke her and we'll get further and the minute she looks like she is uncomfortable we back up, and when she looks relaxed again I say okay, thats it, good girl and she is allowed to go back to eating hay or doing whatever it was she was doing.