I tore my subscapalaris back in 96 and was advised to just let it heal and rehab it. this was around the same time with all those medical break thoughs and i guess my treatment plan was normal - i still wonder though. anyway i remember after 6 months of rehab i could do everything within reason, except throw a ball at 100%, 50% sure but if i went over that i would get serious pain and still do to this day, but only throwing a ball harder than 70%.
after a year of rehab i was in the military doing push ups/pull ups normally, and boxing. i could throw every punch 100% except for an overhand left handed haymaker, basically a mimic of my throwing motion, i still cant throw a ball harder than 70%
Recently i hurt something in the same shoulder and its been 2-3 weeks of rest, ice and ibprofens. it wasnt as bad as my baseball injury but it hurt none the less and does hurt.
im still taking ibprofens 2-3 times a day and icing a few times a day or after activities.
my self rehab has followed:
i did range of motion exercises probably 5-6 days after full on pain (it was slowly building for a week or so then blam), avoiding painful movement, just slow, relaxed; such as the hanging pendulum. i did light stretching too.
i didnt sling my arm but i made sure not to move it much other than when doing my ranged exercises - and i avoided sleeping on it.
i'd say around day 10 i added light swings - since it was my left shoulder hurting, i would only do half backswings righthanded because bringing my shoulder up and stretching my left arm killed then a modified follow through after a almost gravity downswing. I just focused on weight transfer not really putting any force nor stress on my arms.
i added left handed swing day 11-12 i forget, because im going to start hitting left handed with long clubs to protect my left shoulder in the long run. i could do a near full backswing left handed i just watched out on the follow through because coming back up brought pain if i added force.
i just started resistance exercises with a rubber tube nearly 3 weeks out. the pain has become minimal, but there are still a few movements where i can feel it, so im not rushing or going to over do anything. i still dont do full backswings right handed nor sweep full on downswings right or left. just soft, im more worried about the actual movements becoming more and more pain free day after day. i can do full back swings left handed now nearly at three weeks but i only go 3/4th left and right because near 90-100% rh i feel some pain. then i just watch my follow through and only swing at 30% or so while hitting plastic balls at a fence.
there are several exercises the rubber tube can be used for. ill do this for another week or two then add a 2lb weight for another week or two and continue this process until im up to 5 lbs and completing high reps easily.
i also do range exercises now while massaging the area to try and promote blood flow, and break down scar tissue.
im looking at another 4 weeks before i assess where my shoulder is at and hopefully a small bucket is the reward
maybe surgery is the way to go for you and rehab times will vary per person. good luck