For copax, I've learned to shoot a little off center for the thigh. I use my hand to go straight down from my knee and go a little to the left or right of that line. I found it hurts the worse if it's too close to the knee or centered in that line down from the knee.

I'm still flexible enough, ***knock on wood***, to curl one leg under the other so the leg of the thigh I'm shooting is kinda drapped and relaxed. My legs shake sometimes with muscle fatigue, so can't do it standing up.

I generally play music in the back ground with a heavy bass or drum section. Kinda covers up the loud "click" of the injector for me.