Hi guys, i am moving to a new address that's served by optimum online. For TV, i want to get the cheapest package (just basic channels + their HD counterparts).
The prime mover for flexion of the shoulder muscles used are the following: 1  Pectoralis Major Clavicle. 2  Anterior Deltoid. 3  Biceps Brachii Short Head. 4  Coracobrachialis.
Movement and Muscles at the Shoulder flexion and extension. It's another good thing that I got Biggie for these pictures, because flexion and extension are movements in the sagittal planeâi.e., from front to back. So in a drawing they're like 3-D, like coming out at you, and that's a bit beyond me to draw.f muscles in the back contract, they pull your arm back. What exercises make these muscles work? Pushups, pullups, rope climbing and throwing flex and extend the upper arms to work your anterior deltoid, coracobrachialis and pectoralis major, and your posterior deltoid, teres major and latissiumus dorsi.