If its not too far for you there is a place in Chak Neow that is the village just past the entrance to Phoenix golf club in Ban Ampur.
Its run by one of the doctors from Wat Yan hospital, the girls are young but qualified physiotherapists, they are fully equipped with ultra sound, micro tens, heating pads and seemingly a lot of knowledge about backs. Costs b800 for a one hour session so not cheap.
I can probably dig out the phone number if of any interest to you.