I see! interested to know if it was your Supraspinatus Muscle, as that is the one responsible for problems raising your arm above your head and can cause impingement syndrome of the shoulder. It can be caused by an imbalance between the pecs and the scapula stabilizers. Dry needing or acupressure/ deep tissue massage can remove Myofascial trigger points in the Supraspinatus and Pec Minor but also strengthening the other rotator cuff muscles is needed. With boxing you need strong serratus muscles too.
I just saw my homeopath and they did the best they could.
Doc wanted to inject cortisol, but i passed
Saw my trusted chiropractor and he gave me some exercises to do, which i ended up stopping as it made it worse.
I just left it, trained as normal etc and its ok. Some awkward movements like extending ladders, picking up things with arms raised etc can really aggravate it, but all in all, im coping fine and it doesn’t affect training.
I wanted to get into boxing, but those movements aggravated it also, which was disappointing.