Thank you for your consult at DoctorSpring.
You have identifiable reasons for experiencing back pain that is injury. But the exact cause for this can be confirmed with the additional information on the type of injury.
I would like to know additional information to provide you with the best and learned opinion.
1. Do you experience pain in the arms with tingling or numbness?
2. Does the pain localize only in the area of injury or is it radiating to other parts of the body like arms, legs etc
3. Is there any muscle stiffness in the back?
4. Have you undergone any investigations after the back injury like x ray or MRI? If yes how are the results?
Coming to the lump in the bottom
1. Is it localized near anus or on the buttocks?
Since how long you are having it and does swell, feel warm, any discharge or bleeding?
You can reply as a follow up.