One of the most common requests personal trainers and fitness coaches receive from clients is "I want abs!" I think many of you may realize that this is a pretty vague request, and one that I wish to tackle with this blog.
First, we will go over many of the muscles that make up the "core," along with their function, and then we will go over some myths and mis-truths about the core that I promise, even the most well-rounded fitness enthusiasts out there, will learn something new.
Keep in mind that your core includes your entire torso (minus, of course, your arms and legs). All the muscles that surround your spine - neck, glutes, abs, back, scapular, pecs, obliques, etc. can and should be considered your "core" muscles. However, rather than get into most of the intricacies of every single one of the muscles involved, I figured I would break down most of the primary movers and supporters of your core so that we can better understand its purpose as a whole, and how you can improve it!
So, first of all, let's cover your anterior side of your body:
The serratus anterior (/ˌsɨˈreɪtəs ænˈtɪəri.ər/) (Latin: serrare = to saw, referring to the shape, anterior = on the front side of the body) is a muscle that originates on the surface of the 1st to 8th ribs at the side of the chest and inserts along the entire anterior length of the medial border of the scapula.
Not to many people would consider the serratus anterior part of the core. This muscle helps protract the scapula (antagonist of the rhomboids) for overhead movements, such as in presses or throws. Since our arms perform so many actions, especially in athletic movements overhead, I consider the serratus to be a major player when it comes to core/shoulder stability.
Not only that, but I personally find the serratus anterior to be one of the most under appreciated visual cues of physical fitness.
The external oblique muscle (of the abdomen) (also external abdominal oblique muscle) is the largest and the most superficial (outermost) of the three flat muscles of the lateral anterior abdomen.
Beyond helping stabilize the vertebral column during flexion and rotation, the external oblique helps pull the chest downward an action known as the valsalva maneuver. For those of you who are familiar with traditional strength training should know that the valsalva maneuver is a breathing/stabilization technique used to stabilize the midsection during heavy lifting.
The rectus abdominis muscle, also known as the "abs and lower abdominals," is a paired muscle running vertically on each side of the anterior wall of the human abdomen, as well as that of some other mammals. There are two parallel muscles, separated by a midline band of connective tissue called the linea alba ("white line"). It extends from the pubic symphysis,pubic crest and pubic tubercle inferiorly, to the xiphoid process and costal cartilages of ribs V to VII superiorly.
Ah yes, the "six-pack" muscle. The one muscle in the entire body that majority of the population wishes to improve. We will get into more of that later, but realize that besides flexing the spine (forward crunches), the rectus abdominis is one of the most over-hyped muscles (in my opinion) in the entire body.
Besides flexing the spine, the rectus abdominis also assists in contracting to increase abdominal pressure (valsalva) during times of heavy lifting or during childbirth. One function that most people do not know about, is that your six-pack also helps respiration by forcefully exhaling.
The internal oblique muscle (of the abdomen) is the intermediate muscle of the abdomen, lying deep to (below) the external oblique and just superficial to (above) the transverse abdominal muscle.
Besides aiding in respiration, the internal obliques are a major contributor to side to side flexion of the torso as well as rotational stability.
The transversus abdominis muscle (TVA), also known as the transverse abdominus, transversalis muscle and transverse abdominal muscle, is a muscle layer of the anterior andlateral (front and side) abdominal wall which is deep to (layered below) the internal oblique muscle.
One of, if not the most important muscle in your core, although located on the anterior side of your body, the transverse abdominis plays a large part in core stability by contracting the midsection to support structures like your spine.
In human anatomy, the trapezius (/trəˈpiːzi.əs/) is a large superficial muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae and laterally to the spine of the scapula (shoulder blade). Its functions are to move the scapulae and support the arm.
The trapezius, along with the rhomboids, help retract the scapulae (shoulder blades). How is this related to core? Well, many people have weak upper backs, leading to their shoulders hunching forward giving them a minor "hunchback" look, also known as kyphosis.
Anyways, having a rounded upper back can lead to spine mis-alignment, and can actually throw your entire spine, including the natural arch of your lumbar, out of place. For a lot of people, this is where a lot of their troubles originate. Sure, most people end up having low back pain, but it may very well originate higher up their spine due to misalignment and poor support from lack of muscle tone.
The rhomboid muscles, (/ˈrɒmbɔɪd/) often simply called the rhomboids, are rhombus-shaped muscles associated with the scapula and are chiefly responsible for its retraction. They are supplied by the Dorsal Scapular nerve.
The latissimus dorsi (/ˌləˈtɪsɨməs ˈdɒrsaɪ/) (plural: latissimi dorsi), meaning 'broadest [muscle] of the back' (Latin latus meaning 'broad', latissimus meaning 'broadest' and dorsummeaning the back), is the larger, flat, dorso-lateral muscle on the trunk, posterior to the arm, and partly covered by the trapezius on its median dorsal region. Latissimi dorsi are commonly known as "lats", especially among bodybuilders.
Despite being a primary mover for rowing-type exercise (pull-ups), the lats play a large role in spine stabilization.
The erector spinæ is a muscle group of the back in humans and other animals, which extends the vertebral column (bending the spine such that the head moves posteriorly while the chest protrudes anteriorly). It is also known as sacrospinalis in older texts. A more modern term is extensor spinae, though this is not in widespread use.
Think of your erectors as support cables for a suspension bridge. They keep you upright, along with help from the other large muscle groups in your back listed here.
The gluteus maximus (also known as glutæus maximus or, collectively with the gluteus medius and minimus, the glutes) is the largest and most superficial of the three gluteal muscles. It makes up a large portion of the shape and appearance of the hips.
One of the most important muscle groups in your body, not to mention your back, your glutes aid in not only keeping you erect, but bring you back to an erect position from a bent over or squatted position.
Let's go ahead and clear up some common myths or mis-truths about your core.
Working your abs (i.e. crunches) will give you a flat midsection and/or "six-pack."