I do not
know what caused the tendonitis.  My best case guess: either catching
cleans too low (not in the rack) with heavy weight and pushing it back up on my
shoulders or back squatting (not having good shoulder position when I have the
bar on my back), Since I do believe I have very good shoulder
mobility in general( My Front rack is good, my arms go above my head well,
etc…), I don’t think it was caused by bad positions or imbalances (but I
could be wrong!)

I can only
guess that these are the cause because putting the bar on my back causes the
most pain.  Pain can also be caused when I press weight overhead or
raise my arm laterally.

In regards
to addressing the situation, I have not back squatted, C&J, or lifted any
weight overhead.  I have abstained from all activities that involve upper
body pressing/pulling/lifting and cant seem to relieve the symptoms.  The
training I do is, squat with a safety squat bar (which requires no arm
engagement, run, and walk.  So I am not sure what you mean by address the
situation since I am no longer doing the movement (because I don’t
want to make the situation worse)

I do
lacrosse ball (LB) my thoracic spine and chest in effort to get slack in the
system and this helps but very little.  My tissues in my chest are
somewhat sore (when I LB them) and it feels awesome when I LB the thoracic
spine but the tissues are not super sore as I can take a lot of press in
the entire area.

does any of
this make sense??

I do however
have had a tight/sore neck that is gets great relieve form MOB but it isn’t
100%