Missy's Striding Issues

So as I mentioned in the CanAm thread, Missy started having striding issues back in May. We had moved her to start dog in April, and I want to say she might have knocked the jump over once in April, but since it only happened once, we just kind of ignored it. Then in May, she did it several times over the course of a tournament weekend. We can see in videos that the reason she's knocking the jump over is because she's taking off for the first jump way too early. We just couldn't figure out why.

I took her to the vet the following Tuesday and she did a physical exam and chiropractic adjustment, but didn't find anything that was really out. So I took her to a trigger point massage the next week and he found lots of stuff on her left side and he felt that might have something to do with it. I took her back right before the June tournament and he found very little trigger points and told me I didn't need to bring her back on a monthly basis, probably an every other month or so. So June she didn't knock over the jumps. I didn't take her back before our July tournament, and lo and behold she starts knocking over the jump again. She did it so hard on Saturday, that she started stutter stepping before the jump, like she was hesitating. So this is when I contacted a trainer that several other people I know have used. I told her what was going on to make sure she thought this was something she could help with, she was confident she could. So I've been practicing with Missy twice a week, and after each practice session I send her a bunch of videos, and she gives me feedback and tells me what to do next. Here's what we've been doing:

So if you're looking at the flyball lane from the side, it looks like this:

Box----Jump D----Jump C----Jump B----Jump A----Start Line

She had us completely take out jump d, replace jump c with a 2" puppy jump, b and a were set to 7" and do recalls. So someone would hold Missy at the box and I would run down the lane, they let her go and she goes over the jumps and catches me. We did this a couple times, then we did full runs with a replaced with a 2" baby jump and b, c, d set to 7". Then every week or so we would bump up the baby jump height from 2" to 4" to 6". I honestly can't explain why we're doing it this way or how it's supposed to help. But it's definitely helping so I'm not really questioning it. This particular trainer is known for coming up with unique ways to solve problems.