How To Treat Muscle Soreness In Back After An Head Injury?

I had an incident while sledding today where I went off a ramp and landed right on my mid/upper back and hit my head on the ground. My head is fine -no concussions, however my back is pretty sore. I am almost positive it s just muscle soreness, but I may go to the chiropractor tomorrow just to be safe. But for the time being, what would be the best position to sleep in tonight to prevent anything that could hurt it more? Just whatever feels most comfortable?