Any injection too centrally located in the glutes can peg a nerve. I have a back injury and definitely know what pain on that nerve feels like it and you don't want to experience it. If you aren't too meaty or fat back there it's not as deep as you'd think if you're pretty close to the spine but yea from what I understand if you hit it you're way off what you're supposed to be doing.
Personal preference! 1" in the outer thigh, checked with my nursing and military medics for advice on that one. Only once did I graze a nerve and where I didn't spaz or twitch that mother fucker hurt like hell all the way in and even a minute after I was done. Thank heavens I have a high pain tolerance.
I didn't go for the backside because I can't turn as well as I'd like to sit there comfortably for the entire injection so I went with what was easily visible, plenty of room for spacious injections if you're dosing EoD or E3D.
image was from google !
