For the longets time I have been avoiding tri injects, because of the pain of shooting in the front part of the tri, closest to the bi (dont know the technical name) My tris for the first time were lagging behind my bis, because of all the spot growth I got from 5 x a week bi injects. I was trying to figure out a way to shoot in the rear tri by myslef, and sure enough, Grandma is slow, but shes old. I just flexed my tri, marked two lines above and below where i wanted to shoot on my rear tri, raised my arm overhead, and rested my hand on the top of the bathroom doorway, and pretty much stuck the needle straight up. Easy, and painless. Man do I feel dumb.