OK let’s now move one floor upstairs from the core. The focus of the second part of this article series is on the shoulder blades or “scapulae” and the muscles surrounding them. Have you ever wondered what exactly is their purpose? Why on Earth do we have a pair of movable triangles made of bone in our backs?
The answer is simple. Our arms require much greater range of motion in comparison to our legs in order to perform various tasks for which we use them. This holds truth for any land animal, but especially for humans and our closest cousins that spend a lot of time hanging around in trees. So in order to make the shoulder joints more mobile, evolution decided not to “weld” the bony bases of the upper limbs to each other as it did with the lower limbs (that’s what the pelvis is), but to let them float over the rib cage. Muscles in the upper back tug and pull on the shoulder blades in several directions so that their outer tips to which the arms are attached can be put in the optimal position for every single arm movement imaginable. Since there are so many ways in which we want to use our arms, there are also many muscles in the upper back which we can use to position the shoulder blades. Once the scapulae are being held tightly in their optimal place, we can start using mighty Lats, Delts and Pecs to move the arms around.
And here is another nice tip to remember: because all those muscles in the upper back (Traps, Rhomboids, Serratus anterior…) are there to prepare the shoulder blades for arm movement, the obvious and right way to make them strong and beautiful is to learn the right technique for executing back, chest and shoulder exercises which involve arms. For example, putting just a tiny bit of effort in appropriately positioning and fixing the shoulder blades prior to the main movement in pull ups and pull downs will make a huge difference in your upper back development. Furthermore, pulling the shoulder blades down and back towards the spine in bench press not only exercises the upper back muscles, but also makes the pecs more efficient and prevents some nasty shoulder injuries.
We find it interesting to stress the similarity between the way our core muscles and our upper back muscles are supposed to operate. Both give us some freedom to position our bodies in such a way so that limb movements can be executed in the most efficient and safe way. Abs move the rib cage with respect to the pelvis and then they lock the lumbar spine so that the torso presents itself to limbs as a single solid structure, while the upper back muscles position and lock the shoulder blades so that shoulder joints at their tips become safe and sturdy, and therefore ready to support the arms.
Both of these muscle groups are thus not meant to do the work in the so called “active contraction” i.e. to actively move the bones, but rather to be strong in the so called “isometric contraction” i.e. to hold those bones to which they are attached to tightly in position. Since the abdominal muscles are often referred to as “the core”, by following similar analogy we might reason calling the upper back muscles “the crust”… and you must become proficient in utilizing both in order to consider yourself one tough nut to crack!