Category: Human body construction

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!

In this article we shall try to map the human body at the very low level of magnification. We shall see out of what functional regions it consists and explain how that translates to several very general rules that apply to training and exercising. Fortunately, this is not complicated stuff but the importance of this knowledge cannot be overstressed; consider it the first step in your true understanding of how your body works, what it likes and what it doesn’t like to do, and what are the most natural and effective ways to care for it.

To begin with, it is obvious that we have the torso to which a pair of arms and a pair of legs is attached to. Ah yes, there’s also that round thing called head, but other than the fact that it weighs around ten pounds which might turn out to be quite substantial load to your neck in some positions, we don’t need to worry much about it in the gym.

Now let’s first take a closer look at the torso. What does it consist of? Most generally speaking, there are two regions, the upper and the lower part of the torso.

The upper part of the torso is rigid because the lungs and the heart that it contains are securely encased inside a bony structure called the rib cage. Note that while the spine extends from the top to the bottom of the torso, only its bottom half, the so called “lumbar spine” is able to twist and bend. The upper “thoracic” vertebrae are fixed by the ribs and do not contribute to the flexibility of the back at all.

Lumbar region is a totally different story. The only semi-rigid part of the spine is lumbar spine with merely five vertebrae. Now if you think a little about it, having a flexible spine right in the middle of the body where stress forces are highest might appear not to be a rather fortunate idea on the part of our Creator, right? Well, not quite so. We need that flexibility in order to function properly in everyday life. The way the almighty solved the issue is that he provided us with a set of no less than four layers of flat but very strong muscles that wrap around and envelop the spine and the internal organs. Those of course are the glorious abs i.e. the “core” muscles.

Here is a very important point to make. The way the abdominal muscles are supposed to be used is no to actively bend or twist the lumbar spine but rather to hold it still. In other words, they are a muscular substitute for bony rib cage.

Because abs are made out of muscle tissue, they can be relaxed and contracted at will. They can be flexible in one moment and turned very sturdy in the next. This gives us freedom to put the torso in the most appropriate form and position for any particular movement we want to execute with our arms and legs, and to fix it there by contracting the abs. Only after the lumbar region is made rigid are we allowed to start moving the weight around with arms or propelling ourselves through space with legs. Otherwise lumbar spine would suffer.

In addition to abs, we also have deep back muscles, the so called “Erector spinae” structure. Literally, those are the muscles that enable us to hold the spine upright. The best way to think about them is to imagine a lot of guy wires tensing the spine from its top to its bottom. When core and deep back muscles are flexed, the upper and the lower part of the torso unite.

It should be obvious to you now why strong abs and deep muscles of the back are of the utmost importance for practicing any sport. And not only sport – the number one reason for lower back pain isn’t something inside the spine itself, but it’s the weakness of the abs and those long muscles surrounding the spine: flimsy abs and bendy Erector spinae provide insufficient support for the body, transferring the majority of the mechanical stress to the lumbar spine; sooner or later ligaments and inter-vertebral disks in there get hurt, and that is what causes infamous aches and pains.

We suggest that you think about your “core” as of a big soda can put between the pelvis at the bottom and the rigid rib cage at the top. If your core muscles are strong and agile, you will be able to pressurize it adequately so that it can’t be neither bent nor twisted no matter how high the load you put it under becomes. But if the abdominal wall is flabby, it will be crushed. And then you and your spine are in trouble.