Accessory Muscle
[image: image.png] [image: image.png] [image: image.png] Looks to be an accessory infraspinatus. I found one paper about this. link.springer.com/article/10.1007/s00276-022-02917-8#:~:text=The%20infraspinatus%20muscle%2C%20is%20the,innervated%20by%20the%20suprascapular%20nerve .