Im doing planks and trying the twist holds lately. Would this be OK? I’ve rested my shoulders for quite a time and resisted every possible ” Grease the groove” opportunity I have on doing pull-ups and simply do a headstand without stressing the shoulders, except earlier when I had the chance for a basic bodyweight calisthenics demo (sorry!?)- it worked good though and I was stronger to my amazement. Any advice on what specific basic bodyweight training I can do to strengthen the shoulders?