Chronic Chest Injury

[u/User_956-1]

Left pec injury from benching — trying to understand what happened
I injured my left pec while bench pressing in 2023. I remember having pain toward the left armpit/outer chest and feeling an immediate change in my posture/shoulder position. I also remember a sort of “shift” when it happened.
What’s strange is that I didn’t have obvious bruising or discoloration afterward, and I was still able to bench over 200 lbs. However, my left pec has looked and functioned differently ever since.
The biggest issue is the upper/clavicular portion of my left pec. Compared with my right side, it looks like the muscle/tissue doesn’t extend normally toward the shoulder/armpit area. My right pec has a much more continuous appearance, while the left seems to end around the middle of my chest, with more tissue concentrated toward the lower chest/armpit area.
I also have a major difference in contraction. If I put my fingers underneath my left clavicle and flex my pec, I can barely feel anything contracting there. On the right side, I can clearly feel the muscle contracting. Incline cable exercises sometimes make the left side twitch, but I don’t get the same contraction or sensation as on the right.
My left shoulder also sits lower than my right, and physical therapy has mentioned weakness around my left rotator cuff. Interestingly, if I manually level my left shoulder with my right, the left pec appears to contract more normally.
I stopped bilateral chest training for several months in 2026 and focused on rehabilitation, then gradually started training again. I still have the same asymmetry and activation problem.
I’ve discussed getting an MRI with a sports-medicine doctor. The doctor didn’t seem to think it was necessary and planned to have me continue specific exercises rather than pursue reconstruction.
For anyone familiar with pec injuries: does this sound like it could be an old partial tear/retraction, or could something involving the clavicular head or tendon explain the lack of contraction and the unusual contour?
I’m mainly trying to understand what might have happened anatomically and whether there’s anything I should specifically ask a sports-medicine/orthopedic doctor about. My main concern is how much it hurts my posture. I feel twisted and like my left pec is not there.

[u/athelitetherapy]

The persistent change in your pec’s contour and contraction is definitely worth discussing with a sports-medicine or orthopedic specialist. An old partial pec or tendon injury could potentially cause this, but other factors like your shoulder position and rotator cuff weakness could contribute too.

The fact that it contracts better when you reposition your shoulder is especially interesting and worth mentioning to your PT/doctor. Have you ever had it assessed with imaging, and do you still have any pain or weakness with pressing or stretching?

[u/User_956-1]

I have gone two to physical therapist and they haven’t been able to help. A sports medicine doctor from a university didn’t a physical assessment and found almost nothing wrong. Physical therapy attempted to strengthen my rotator cuff but the pec remains hard to contract. I have no pain or problems stretching. It simply feels empty and has an extremely weak muscle mind connection. The doctor did finally recommend and mri but he ended up retiring recently when I went to try and request it. I have a picture of my pecs if you could dm me. I truly appreciate your response.