Out of all the rotator cuff muscles responsible for shoulder pain, nothing is more influential than the Subscapularis. The Subscapularis is a short, powerful muscle located on the anterior end of the scapulae that internally rotates the arm at the shoulder. Usually, when it gets tight it can set all the posterior chain muscles of the scapulae directly into spasms, which invariably leads to rotator cuff impingement. Also, in this specific section of the scapulae/shoulder, there is a muscle called the Latissimus Dorsi. This is a major muscle group that is highly responsible, along with the Subscapularis, for shoulder pain.

In this video, I should you how to specifically get at the root of many rotator cuff injuries. It's always best to incorporate correct exercises along with these types of release techniques after they have been implemented. Enjoy :)