In our previous three posts, we talked about the two deeper muscle lines in the arms, as well as, the superficial chain in the front of the body. This week we’re going to introduce the last muscle/fascial chain- the superficial back arm. If you think of the deep lines as our stabilizers, the superficial lines are the real power behind reaching overhead, reaching out to the side, and pushing/pulling. It’s important to realize that these muscle chains/lines all work together. If the deeper lines are restricted/stuck, they will compromise the more superficial muscles and vice versa.
In terms of function, this muscle chain is responsible for controlling the movement of our arm behind us, as well as, out to the side. To do that we need larger muscles which we get in the Trapezius and Deltoid. Both of these muscles feature multiple functional parts capable of moving the arm in multiple directions. This makes them powerful abductors. From the Deltoid, this arm line travels down the lateral septum (which separates the muscles in the front of the arm from the back of the arm). It then connects to the common extensor group (purple in the picture above). The extensor group originates on the lateral epicondyle and travels down the back of the forearm and hand to our fingertips.
Here’s a video to walk you through the muscles in this chain and to show you how to stretch them: