I'd disagree, I don't think pinning a muscle after its been worked is the best idea. Now I have no proof of this other then my own experience, so I could be wrong. But any time I inject a muscle that i just trained, it always causes a lot of post injection pain and swelling. If things are going to knot up or swell, this is a sure fire way for this to happen...at least it is in my case. My guess is this can happen because the muscle has already had a lot of trauma inflicted on it, and your just flaming the fire, kind of like pouring salt on an open wound.
I've always found the best time to inject a muscle is before i train it, if I have shoulders then I inject shoulders and then train, or whatever the muscle is. For starters this doesn't cause the problem associated with post training injection of a muscle and it seems to help disperse the oil more efficiently. Now I don't always inject a muscle right before I train it...it doesn't always work out that way, if it doesn't I'll just pick some spot that has not been injected recently or trained.
I intended for Biceps only there AJ. I have had 2 bad Bruising events with bi shots done prior, even 2 days before the arm workout. As little as 1cc. Maybee a bigger bicep can soak it up better, but I contract real hard, and that oil bolus is a ball that aint gonna go away.
Other spots, I'm just thinking of not having post shot pain interfer w/ a leg workout.
Delts rarely give me any prob, but I've overused them too long IMO, so I'm trying to give 'em a break by spreading them around.
I do lots of my shots preworkout. Try a blast of Prop, or 4cc of Sus 1 1/2 hrs pre workout. Not as good as 3 Dbol, but not bad.