The Rotator Cuff group of Muscles
In this 2nd Video I explain about shoulder joint stability.
The Gleno- Humeral joint.
The four Rotator Cuff muscles:
3. Teres Minor
I also mentoin the other stabalisers the labrum, a piece of fibrocartilage that deepens the socket helping stability. The extra ligaments that provide some more and finally the negative pressure in the joint that basically helps keep the joint in its socket by negative pressure.