I did OK with some light strengthening after the pain level & symptoms were down to a 0-2 range.

like the wall pulley w/ adjustable weights - .5 up to 5 lb only
laying on a bench/table doing some .5 lb - 5 lb side lift and rotation

and as I began to feel up to it a lot more of the normal activities around the yard & garden.

I do think starting with an aligned skeleton (expert chiropractic? or spinal PT) and good posture really helps. If there are misalignments you can't really progress until those are fixed. Like trying to build a house on a broken foundation. Chiros can adjust wrists, ankles, shoulders, ribs, elbows, hips, and the all important c1c2 ( that takes some extra training some don't do it.)

Then if there are trigger points - those need to be resolved - trying to stretch a muscle with a trigger point in it is a waste of time- get rid of the TrP first. And when you get rid of that one, other latent TrPs may show up and those need to be treated too.

I think trying to isolate single muscles and do too many reps just sets you up for for troubles, doing large overall movements works better for me.