Today we pick up our core training series with the lateral core system. We’ve already talked about the anterior and posterior aspects of core training, and after today we will be left with only the rotational aspects. The muscles of the lateral core are involved with a ton of movements, including many found in the anterior and rotary systems, but they are really isolated by a movement called lateral flexion. This is the action of side-bending the spine, bringing one arm pit closer to the pelvis. As we’ve talked about in previous posts, the name of the game in core training is to resist movement, so today’s post will be all about anti-lateral flexion. When trained properly, the lateral core musculature acts to keep the spine neutral when there is a force (gravity, a weight) trying to create lateral flexion of the spine.
What muscles are involved with anti-lateral flexion?
Several muscles are involved in the act of resisting lateral flexion. The two most noticeable are the internal (IO) and external oblique (EO) muscles, but also involved in the process are the transverse abdominis (TVA) and quadratus lumborum (QL). The IO, TVA, and QL muscles are all deep muscles which lie underneath the more superficial rectus abdominis (RA) and the EO.
The External Oblique (EO)
The external oblique runs from ribs 5-12 down to the crest of the hip bone. The EO is innervated by the thoracoabdominal nerves as well as the subcostal nerve. One extremely common complaint among women exercisers is the desire to get of their “love handles.” This area of abdominal fat, found above the hip and under the ribcage, lies right ontop of the external obliques. Because of this, many people attempt to side-crunch their love handles away, thinking that by working their external oblique, they will be reducing their abdominal fat. Unfortunately, there is no amount of side crunches or ball twists that will reduce the body fat ontop of the muscle. If you want to lose your love handles, the vast majority of your work must come from cleaning up your diet. This is obviously a topic which can and will be it’s own post, but you will absolutely never out-exercise your nutrition.
The Internal Oblique (IO)
The Internal Oblique muscle lies below the EO and just ontop of the TVA. As you can see with the picture above, the EO must be removed in order to see all of the IO. The IO originates on the Inguinal ligament, Iliac crest and the Lumbodorsal fascia and inserts into the linea alba and ribs 10-12. Like the EO, the IO is innervated by the thoracoabdominal and subcostal nerve, as well as the iliohypogastric and ilioinguinal nerves. This is important to note because things that are wired together tend to fire together– meaning that when two muscles share common nerves, they tend to work together. In this case, the IO and the EO work together to stabilze the spine. The IO also plays a very important role in breathing, which is a topic that we will also cover in a separate post.
The Transverse Abdominis (TVA)
I spoke at length about the TVA in my post about anti-extension stability. Check that post out for a more thorough explanation of the job of the TVA, and also know that it helps support the spine laterally as well.
The Quadratus Lumborum (QL)
Ah, the poor QL muscle. It gets some really bad press for a lot of things that just aren’t the QL’s fault. One of my favorite therapists, Dr. Kathy Dooley, has a great write up on the QL here: http://www.drdooleynoted.com/anatomy-angel-quadratus-lumborum/
The QL is a muscle that is meant to help other, larger muscles stabilize the spine. It’s meant to help the erector spinae and multifidii support the spine and keep it from flexing forward. It’s meant to help the obliques support the spine from side to side. When erectors, obliques, or rectus abdominis aren’t doing their job, the QL is your body’s last resort to maintaining an upright spine, and as such, the QL gets over-worked…a lot. If you sit a lot with poor posture or if you don’t strengthen the other hip and core muscles around the QL, your QL will have to do a job it’s not designed to do. An over-worked muscle often becomes a painful muscle, and this one of the very common reasons for lower back pain. Since the QL plays such an important role in spinal stabilization, we certainly need to strengthen this muscle. However, we also must make sure to strengthen the muscles of the hip and the core around it, to make sure it does not become over-worked.
Stop doing this:
Side bends, side crunches, or anything where you’re repetitively taking your spine out of neutral as you try to isolate your obliques. I don’t care how many side crunches you do, your love handles are only going away if you change your nutrition. Similar to the traditional crunch or sit-up, a side crunch or side bend takes the spine out of neutral and repetitively doing so can lead to back pain, disc damage, etc.
Start doing this:
Side planks and loaded carries. The side plank is simply holding a plank position, except on your side. You balance between your elbow and your feet and you maintain a neutral spine with gravity attempting to pull your hips down towards the floor. Holding this static position is the very definition of lateral core stability. Once you can hold this position for roughly 30 seconds per side, you can start to add various movements to the side plank, or move into loaded carries.
Loaded carries are a group of tremendously beneficial exercises that just about anybody can do. One of the most basic forms of a loaded carry is called a suitcase carry. Simply hold a weight at your side and take a walk. We usually carry for 50-100 feet per side set. The weight on one side of your body attempts to pull you into lateral flexion, while the core musculature of your opposite side works to keep you upright. The great thing about loaded carries is that they have the added benefit of improving grip and shoulder strength, while also getting the exerciser onto their feet. This is an exercise that almost anyone can do in some capacity and has a great tendency to improve multiple areas of fitness.
Thanks for reading!