I have never encountered Stringhalt, and do not know a lot about it. The only "cure" I have ever heard of for it is surgically removing the tendon that is causing the involuntary flexion. The only people I have ever heard of opting for surgery is if the horse that has Stringhalt has it so bad that the horse is literally kicking itself in the belly.
If you want more info on it, you could try doing a Google search. Go to
www.google.com and type in "Stringhalt Horse". That should pop up some info for you.