Trotting withOUT command????? Help please!!!!!!!

My QH mare starts to trot around corners whenever someone rides her. She's not doing it to be mean, but I would like her to not do it, just in case someone rides her and doesnt know, and loses their balance......etc..............

And she is a former barrel racer...i would like this problem to be fixed and I am so willing to try it. Thanks! :)

My mare used to do this all the time- especially on the trail.... The way I broke her of it was everytime she started trotting without me telling her to- I stopped her and backed her. I then made her stand still...if she tried to move out again without a cue, I would back her some more! Eventually she got the point - but in the beginning you can cover quite a bit of ground backwards! Lol
This worked really well....

I do think that would work. Thank you so much! :)