I've had partial dislocations on my left and only during loops (student/solo stuff). First time it took a couple weeks before I felt good enough to attempt frontloop again and all was well the first loop but the second one(same freefall) I think I may have heard a pop and it hurt even more than the first. Ahead 6 weeks before trying loops again, first backloop ok.. then last attempt before tracking and my arm locked in sort of a delta position but with a bit of twisting I was able to unlock it and it was sore but not as bad as the previous one. I had been doing rotator cuff exercises for 3 of the 6 weeks (first 3 just to let soreness subside fully). I didn't have issues with shoulder during backloops prior to the first incident. I cradled my arm against my body at first(sling position) which didn't do much for stability but WAS able to get into a box, stabilize, and pull at the right altitude even though my left arm was very weak and shoulder in pain. It scared the hell out of me flopping around in the air and it also disheartened me because I love this sport and this could end it for me before it even really begins. It's been about 3-4 weeks since that last skydive and there are still certain movements or positions that cause pain for a moment, I have new clicks and small pops when I rotate and move my arm all around, but I basically have full strength back. Doctor I saw didn't really care since it wasn't acute pain and I had full movement so didn't get to have it scanned, physio therapist thought it may not have been a full dislocation at any time since I had full, albeit slow, movement and good strength after only 3-4 days. It's not so much how strong your shoulder is but how quickly things happen in the air that your strength may not help with in time.. such as catching the relative wind in box position while coming out of a loop. Sure it's not a strong force if I'm prepared for it but it just threw my arm quicker than I expected it to. I'll be doing strength/flexibility exercises for the winter and hope all is well for next season, even considering a brace of some sort. There are many shoulder posts on this forum, I recommend going through them.