So this has been going on a couple of years now, but certainly not getting any better. There’s always this indescribable stiffness or weakness in my left shoulder pressing. I noticed more recently that it has been affecting my pressing, and I’ve begun getting left pectoral pain as well.
Obviously it’s pretty vague, so you can’t make a good diagnosis. Perhaps this is helpful: external rotation is significantly more difficult on that side. If I lie on my side and do the DB external rotation, I can do far fewer reps with my left side.
Any ideas? I’ve been stretching, doing raises, internal/ext rotation, etc…
Hammer the upper back. Rows, chins, face pulls, reverse flies. Really focus on retracting the scapula. This will put your shoulder in a more mechanically better position to press from. When you do press. Start with dumbbells with a neutral grip and ensure those are pain free before you return to barbell pressing. Also, perform soft tissue work on the back of the shoulder with a tennis/lacrosse ball. Trigger points can be pretty nasty back there. Good luck!
mmash34 is right. But add doorway stretches (hand and elbow on post, upper arm horizontal, turn torso in opposite direction). It is likely to be an inflammation somewhere where the ligaments meet/cross/overlap (tendonitis, bursitis, other itis). Rest might not be uncalled for.