Depending on what is causing the pain, there are many homeopatic things you can do.... Some as simple as warm shower/bath to losten up the tense tissue, to back rubs from someone who cares, using a tennis ball for direct pressure on the aflicted spot (not on bone, but deep tissue). If it is a compression due to the horseback riding, there is inversion tables, warm and cold pack made out of common househole items... the list is almost endless. Again, it all depends on what is causing you the pain in your back.
Have you attempted to recreate that motion while not on a horse? There is a rocking movement you can do on the floor, couch or bed that might be helpful.
I personally generally recommend large doses of MSM powder for pain.<br />
Homeopathy doesn't work that way, where one can just tell you what to take ba<x>sed on knowing that you have back pain. There is much more to it.
It is biological sulphur. It is something that used to be much more prevalent in our diets, but with modern farming methods is now almost deplete. It is a pain reliever and detoxifier.
Homeopathy ! Lol ! You might as well just use water ! - It's the biggest scam out there !