You could do this with a lengthy, complicated series of midsection/trunk exercises, or you could hit every associated muscle in the correct balance and proportion by walking.
Your body was built to walk - you are a walking machine.
I had a blown L4/L5 going into basic training and was immediately walking 5-8 miles per day. It was very painful and debilitating for the first week ... and then it was gone. I believe the muscle action pulls the spine back into proper alignment and gives the disc nowhere else to go but where it belongs.[1]
If you look, you will find this to be a very common anecdote.
[1] IANAD and obviously cannot speak to severe trauma, fractures, etc.