What Causes Abdominal Muscle Pain During Spinal Rehabilitation?

Hi, may I answer your health queries right now ? Please type your query here...I broke ,my back L4 & 5 4 years ago and reinjured by riding horse. Now in therapy to strengthen low back and I want to know it that is what is making my abdominal muscles hurt so bad too. I can't stand very long.
I paid for an answer once before and never got an answer, but the money was deducted from my account. Do I get this answer for free?