Just as a quick update, I had the PRP (plasma-rich platelet) injections on Friday. Two separate injections, one for the tear in my infraspinatus, one for supraspinatus. Some interesting notes/thoughts on how things went:
* Either I was initially mis-diagnosed (obviously possible) or my shoulder has miraculously gotten better to some degree. Originally I was told I had full thickness tears in both infraspinatus and supraspinatus, with infraspinatus maybe ~1/4 of the way through and supraspinatus as much as ~3/4 of the way through. He seemed to have more difficulty finding the tear in infraspinatus on Friday (5 months later), and said it looked like a partial tear, as opposed to a full thickness tear. On supraspinatus he said it looks like a full thickness tear, but by his guess maybe ~1/3 of the way through. These are obviously much different (and better) diagnoses, so I'm not sure what the hell happened. Maybe HST is magically causing my shoulder to heal? There actually is research showing that a small minority of people actually recover enough from full thickness tears that they're no longer visible on MRI, so maybe it's possible that resistance training is more magical than we realize. Or, like I said, he somehow initially misdiagnosed this.
* The procedure was WAY more painful than I realized, particularly for infraspinatus. They draw, spin, and then inject your own blood back into the injury site without anesthetic, and the needle is decent sized. The first injection hurt so much I almost passed out afterwards. The second one was a lot better.
* My shoulder is way, way more sore than I realized it would be. At rest it doesn't really hurt, but it feels like somebody punched my shoulder a few dozen times or something when trying to raise my arm above my head and such. Taking a shirt off is still pretty difficult.
Given the above, I will probably end up taking off until ~Saturday, unless things drastically improve by Wednesday. That said, the shoulder is feeling better pretty quickly, so I'll play it by ear. Either way, I may wind up doing an even lighter initial block, possibly 20's for lower body and 15's for upper body, preceding the normal cycle, given the longer than usual detraining (I'll have worked out basically once in a month or something like that by the time I start back).