I have had brilliant results from a trusted 'back lady', quite often the rescues that I take on have back problems, some I can fix myself and others need her help. Quite often it is from the wild ones rearing and going over backwards, hurling themselves into walls, other times it is a big buck, an accident or rolling awkwardly and getting cast. The spine of the horse is slung between both sets of legs and it does get problems. But first like has already been said check the tack! Saddles are the worst culprit then bits. If in doubt try lunging and riding bareback and see if the problem is still there. Hard to do if its outdoor napping though so stay safe.

But there are many quacks that charge the earth and do nothing so be wary and go on a good reputation