As a professional, understanding the dynamics of the shoulder can help us better serve our clientele.
In this article, the authors reviewed the roles of the shoulder muscles in task specific mechanisms during medial and lateral rotation. They found that during medial rotation, the subscapularis was called into play heavily. During lateral rotation, the supraspinatus, infraspinatus, serratus anterior and lower trapezius were called into play.
While this is no surprise, it was later noted that by increasing the rotational forces (resistance) that these muscles increased force output while the global movers (pecs, lats, delts) did not increase force.
Of interest, the scapulothoracic stabilizers contracted with more force as the torque increased. This provided additional stability at the ST joint while the deltoids provided dynamic stability.
Interesting! Another article proving that ST stability is the way to go! Think about throwing... The lower body & trunk are the power producers, the ST joint is the regulator/transmitter and the GH joint is the delecerator!
Cool! Cool! Cool!
Try this exercise to improve shoulder mechanics and improve injury resistance. Enjoy!