Core Muscle Guide

A Guide to the Muscles in Your Core

When many people think of their core muscles, they think of only the abdominal muscles. But there is much more to it than just the abs. The major muscles of the core run from the front of the belly around each side of the body to the mid to lower back.

The core is made up of five main parts:

Rectus Abdominus

These are the ones most people think about when referring to abs or a six-pack. Running from the sternum to the pelvis bone, they connect the upper torso to the lower on the front of the body.

Obliques

There are actually three types obliques: internal, transverse and external. They all work together to ensure we can tilt and twist the torso.

Intercostals

The intercostals support the ribs and are found in three different layers: External, Internal and Innermost. The way to think of them is the Innermosts run on the inside of the ribs, the Internals run between the ribs and the Externals run on the outside of the ribs.

Serratus

Often called Boxer’s muscles, these are the muscles that allow a boxer to throw a punch. Coming in both anterior and posterior, they run from the back under the arm and around to the front in the area around the abs. Along with the intercostals, these are the muscles that connect the back of the body to the front, thus forming a cage around the body providing upright support. The abs allow us to bend forward and straighten up; the obliques allow us to tilt and twist.

Erector Spinea

As you can imagine by their name, these are the muscle that run most of the length of the spine, from the tailbone to the back of the skull. Their job is to keep your spine straight and erect.

The body uses these core muscles to support itself in a vertical plane called the transverse plane and two vertical planes, the coronal – side to side and sagittal – front to back. To demonstrate a plane, let’s take the movement of walking uphill. While it is common to think of the leg muscles doing all the work, they are actually just propelling the body forward. Without the core stability of coronal and sagittal planes, the body would not adjust itself to overcome the angle and would either tip over forward or backward.

Because our core muscles are used for balance, it is important to include strength training routines that keep them strong – especially as we age.

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