I never had a hackhammer type used hard, it was gentle to mod, and worked so much better. I can not tolerate the neck cracking; I also have herniations though.
My best work out, is pressure points. The doc starts low and works up along the spine and across the traps;

I also get a deep massage until I cry....I may flare just a bit, but the pain I am in to get it done I really do not notice. The lumbar generally......I need deep kneeding in the hips butt, back to get any relief to walk any more...
More herniations there and S&I issues.
Some days I can not stand any more. Then I need the massage and trigger points along with a shot of Toradol The miracle med Feel better tied