I HATE bicep injections. Can't stand 'em. They are the hardest part for me to shoot. Not sure why. Hurts a bit more than any other site for me. But I think it's the mental part that sucks the most. I can't jab the needle in fast in the bi. One time I did that, my muscle locked, and literally bent the needle. That hurt like a motherfuck. Got a pretty good sized bruise. So I need to do the shots REALLY slow.
But what they said is true. Find the peak, then relax the arm. I do bicep shots with my arm bent, but my palm turned down, and I totally relax. My bicep isn't much more tense this way that when my arm is straight, and I'm more comfortable with it.
I still do 'em.
But I hate it every time.