The Core Musculature

Understanding the Core Musculature Mark Greenberg MD The core musculature is responsible for supporting the spine and trunk and translating the energy from the upper and lower extremities into efficient movement. Creating a strong core will allow you to keep optimal body alignment for all athletic activities. This is especially important for all athletes as creating a strong core, will reduce your fatigue and increase power. The most visible, and well appreciated of the core muscles is the Rectus Abdominis (RA), the muscle down the front of the abdomen, which gives you that ‘6 pack’ look. While the RA will allow you to flex your trunk (think sit-­‐ups), it is probably the least important. Functionally, the muscles which stabilize and support your spine, the deep trunk muscles; Transversus Abdominis, Multifidus, Internal Oblique, External Oblique, Quadratus Lumborum, Ilopsoas, and Erector Spinae should be the focus of core training (Figure 1). Figure 1 These deep muscles, although are not prominently visible but are responsible stabilizing the trunk, and transferring essential motion of the body. The trunk of the human body moves in three planes; sagittal (bending front and back), transverse (rotational), and frontal (side bending) (Figure 2). It is essential as trainers, to work the body in all three planes, and in both directions to ensure balance for proper functioning of the muscular skeletal system. Strengthening the core in all three planes will also decrease injury by preventing excessive force on all structures of the kinetic chain. Many of the exercises we do using Lagree Fitness work the body in these 3 planes, and it is important to know which plane you are working in. (Figure 2) Figure 2 Motion in the sagittal plane causes flexion and extension of the spine. The typical
exercise in this plane of motion is ‘sit ups’ and crunches (Figure 3).
Figure 3
The opposite (sagittal plane in the negative) direction would be backwards bends
(think wheel or full locus pose in yoga) (Figure 4).
Figure 4
When we work the body in the positive direction of the sagittal plane, the main
muscle working is our Rectus Abdominis, RA (the six-pack muscle). The RA is
responsible for trunk flexion so it’s the antagonist to the Erector Spinae, which
bends the spine backwards. The giant crunch, super crunch, megaformer crunch
and tailbone angel crunches work the RA and give you that awesome 6-pack.
The Iliopsoas, also assists with motion in this plane flexing the hips. Serve the
platter, chest opener, and chest fly work the Erector Spinae, the muscles
stabilizing the spine in the negative sagittal plane.
Motion in the transverse plane or the rotational plane is when the body twists
from the hips and shoulders; think swinging a baseball bat or turning around to
look over your shoulder while your changing lanes on the freeway. Transverse
plane exercises are performed by a variety of muscles, but the primary muscle is
the External Obliques. Kneeling torso twists (Figure 5) are the classic exercise,
working the oblique muscles in the transverse plane.
Figure 5
The External Obliques turn the body in the opposite direction that they contract
(figure ). Thus if you want to train the right external oblique muscles, you need
to do torso twists in a counter clockwise direction (toward the left). You will
also be working the left internal oblique muscles, and all of the muscles that
stabilize the back. Other exercises that train the obliques in the transverse plane
are mermaid twists, soul train, single arm rows, and angel torso twists.
Movement in the frontal (or side-bending) plane, occurs when one bends laterally
away from the midline of your body. Mermaid crunch (Figure 6) is the prototype
exercise that works the body in the frontal plane.
Figure 6
Other exercises that work the muscles in the frontal plane, include side plank,
scrambled eggs. The Obliques, Quadratus Lumborum, Multifidus, and Erector
Spinae are the main muscles the body uses for side bending.
While it looks good to have a nice six pack, it is important to train all the core
muscles to ensure creating strength in all three planes, and in both the negative
and positive direction to maintain a balanced body, and remain pain and injury
free. When choosing exercises for a specific routine, keep in mind that different
exercises work the core muscles in different planes, which will improve functional
fitness, and sculpt the torso evenly.