Back Arm Line Anatomy
Rough Transcript:
From the upper thoracic spine, the rhomboid begins the deeper back arm line and immediately begins the “Scapular Sandwich” of rotator muscles. The rotator muscles surround the head of humerus just like the ocular muscles surround the eye
“These four muscles of the rotator cuff control the rounded head of the humerus in much the same way as the ocular muscles control the orbit of the eye…’The brain points the arm and finger as accurately as it points the eye. In the orbit and at the shoulder, the eye and the humerus are free to rotate (or swing) in front-to-back and side-to-side planes, and also around their long axes. And in both cases there is a precise arrangement of muscles aligned and attached to power each of these movements.”
When asked how he shoots so well, Wild Bill Hickock, one of the greatest marksmen of all time, said he just looks at what he wants to shoot. SO simple, yet biologically so true.
This deeper back arm line continues through the triceps, with origins on the back of the shoulder joint and humerus, and then wrapping around to the olecranon of the ulna, your elbow.
This line continues to the outside of the pinky finger
The more superficial back arm line consists primarily of the Trapezius and Deltoid
“The SBAL is a single fascial unity from the spine to the backs of the fingertips”
A single fascial unity that covers such a huge expanse of space, our back arm line is built for support and stability. The muscles are hardly separate and can almost be seen as one large swath across the back and over the shoulders.
“The trapezio-deltoid complex can be seen as one large triangular muscle that focuses down on the outside of the humerus from a broad attachment along the whole upper spine.”
So we start to see how the back arm line becomes the canvas, the foundation, upon which the front arm line can perform its magic. Together, they dance, separate they just spin in circles.
“The Back arm line…acts mostly to limit and contain the work of the front arm line. ”