HI Guys, my horse has constantly had back issues and poor saddle fit. She is very sore in her lumbar area and has a few vertebrae out of place. I have had a chiro out for her which helped temporarily. What do you guys suggest to keep her more comfortable? Anyone use therapies such as TENS machine, PEMF,Bemer or others? If so, what are some affordable options to keep her feeling better. THis problem is raelly affecting our runs and I just want to fix it already

I would rule out Kissing Spines before trying alternative therapies.  Meso therapy (back injections) and can relieve your horse's pain. Often your horse will compensate and carry herself differently if suffering from sore stifles, hocks, SI pain. It's probably not the solution you want to hear, but I would consult a good lameness Vet that specialist in performance horses before trying other therapies.  You will probably spend the same amount of money in the long run.  Best of luck in resolving the issue.

Start with X-rays of spine at local vet. No matter the issue, chiro won't fix it. 

Acupuncture.  

Have you had her ovaries checked? Reproductive issues can also cause back pain.