What kind of back injury and what kind of gear? A normal/upper range test level is good but not sure I would use much else. Peptides like cjc w/dac, mk677, and bpc157 would be good as well.
I fractured my sternum in a car accident about 18 months ago, also damaged my PCL. I was on 250mg/wk test c and maybe 4mg/wk of cjc w/dac. My physical therapist said she couldn`t believe how fast I healed.
The OP needs to state the nature of his back injury before anybody speculates any further!