I am a professional bmx rider and I happen to fall on my bike during a riding session and hit my lower back really hard! I can walk and bend over and back. But it is swollen really bad and pains a lot I only got it tonight but should I worry about anything or see a doctor? Thanks in advance!
Yes, I would suggest you to take advice from a doctor. You will also need to get an x-ray of your back to make sure that nothing has happened to your bones. At present if you want pain relief than you can start taking muscles relaxant like moral or MySpace.  Also try to use ice at your back local application of diclofenac ointment will also be helpful.