The final chapter in our exploration of core function is my personal favorite, the rotary core. It’s my favorite piece to the puzzle because there are so many wonderful variations of rotary exercises out there with fantastic risk-reward ratios.
We’ve already covered:
–The Anterior Core
-The Posterior Core
–The Lateral Core
Through our discussion, we have already come to conclusion that your core musculature is capable of producing trunk motion, but it’s most essential role is PREVENT motion of the trunk. The anterior core resists trunk extension. The posterior core resists forward flexion, and the lateral core resists lateral flexion of the spine. The more often we take our lumbar spine outside of neutral, the more we are asking for problems in the discs and surrounding structures close to the spine. This point is not debatable and might be even more important in the case of rotation.
As world-renowned physical therapist Shirley Sahrmann states, “during most daily activities, the primary role of the abdominal muscles is to provide isometric support and limit the degree of rotation of the trunk…A large percentage of low back problems occur because the abdominal muscles are not maintaining tight control over the rotation between the pelvis and the spine at the L5- S1 level.”
So, the job of the core is to prevent lumbar (lower back) rotation in order to keep the spine neutral. Why? Well, remember back when we looked the anatomy of our spinal column.
We learned that the area of the neck is referred to as the cervical spine, the area of your spine from about the top of the shoulders to the bottom of the ribs is known as the thoracic spine, and the area from the bottom of the ribs to the top of the sacrum is known as the lumbar spine, as shown below:
As you can see, each vertebra is named (C for Cervical, T for Thoracic, etc.) and numbered starting with C1 in reference to the proximity to the skull. C1 is the closest vertebra to the skull, T1 is the uppermost thoracic L5 is the lowest lumbar vertebra, etc.
How does this play into our discussion about rotation? Each segment of your spine is capable of a certain degree of rotation range of motion. Attempting to surpass this range of motion can and will result in serious injury, such as a tearing of the annulus of the disk, if performed repetitively over time. This annulus tear, if left untreated can eventually lead to a disk herniation.
The lumbar spine, or lower back, is the most common site of back pain, and lumbar rotation is one of the most common causes. The reason for this is pretty simple. Each segment of the lumbar spine is capable of only 2 degrees of rotation. Rotating just 1.5 degrees further than this range of motion, repetitively over time, has been shown to create the annulus tear that I just mentioned. That is an incredibly small window with which to work and because of this, using exercises which create lumbar rotation are almost always forbidden when you see a PT for back pain, and should be completely removed from all exercise programming as a preventative measure. There are SO MANY wonderful exercises that we can use to challenge your rotary core without creating lumbar rotation, that the use of lumbar-rotating exercises make zero sense. Remember, people with sedentary jobs sit, often with a flexed lumbar spine, all day long and add rotation for things like answering the phone, opening drawers, etc. This is an extremely common mechanism for back pain, and adding more rotation at the gym is a bad idea.
On the other hand, the hips and the thoracic spine are capable of wonderful amounts of rotation, and are both highly mobile joints. Rotation of the upper body should occur almost entirely through the thoracic spine, and people should learn how move with their chest.
Stop Doing This:
Russian twists, scorpion stretch, seated trunk rotation, full range of motion window wipers, or any other motion which produces repeated rotation of the lumbar spine. The russian twist is an incredibly common exercise meant to strengthen the rotary abdominal muscles in which you are seated, essentially balancing on your tailbone, taking a medicine ball or other object side to side. I’ve even seen this exercise advertised online as a way to “reduce your waist.” Since we already know that spot reduction is a myth, I’m not going to go too far into that detail. What happens with the russian twist is essentially the same thing that happens when people sit in their chair and rotate for something at work, except they don’t do that at work for 3 sets of 40. The hips and lumbar spine flexes and excess rotation is seen at the area of the lumbar spine. This, again, is a primary cause for annulus tearing in the disk.
The Scorpion involves lying face down and then bringing both legs over one side of the body, then the other, without moving the upper body. So here, we prevent thoracic spine movement (the place we actually want to move) and create it in the lumbar spine (the place we want to keep still). Same goes for the seated trunk rotation and full range of motion window wipers. Partial range of motion window wipers, when executed slowly and properly, can be safe and effective. The knees should move only 15 degrees or less to each side of a vertical line, as this is the summation of the range of motion that each lumbar segment can go through. These must be done with great care, but can be an effective trunk stabilization technique.
Start Doing This:
Birddog, Palloff exercises, chops and lifts. The birddog is a great starting place for rotational stability training. Get down on all 4’s, keep a neutral spine, and start moving things around. Kick a leg, reach an arm, go slow, go fast, etc. This is an exercise that a HUGE range of people are capable of doing, and can be made extremely challenging for the more advanced exerciser/athlete. As you create range of motion in your extremities, your core musculature is working to resist rotation in your lumbar spine.
A Palloff Press or Palloff hold is simply attaching a band, tube, or cable pulley to an anchor point which is set to be about chest height, holding that implement in front of your chest, and extending the arms directly in front of the chest to create a rotary challenge. The band, tube or cable is trying to pull you into rotation, while your core muscles work to resist it. This can be done in a hold for a certain amount of time or for repetitions (pressing in and out). This is another exercise which can be done by almost anyone, and can be made brutally hard. You can do this standing, on your knees and even lying on your back.
Chops and lifts create a diagonal pattern of movement, either going from one shoulder down towards your opposite hip (a chop), or going from one hip up towards your opposite shoulder (a lift). This can be done using a cable, band, med ball, rope, etc. and can be done standing, kneeling, or lying on your back, again making this a very useful exercise for many populations. The key with these exercises, as with the birddog and palloff press, is that the movement comes from the arms and shoulders, NOT the lumbar spine. From the bottom of your rib cage to the top of your pelvis, zero motion should occur.
This concludes our exploration of core function, so let’s sum up:
Stop Doing: russian twist, scorpion, seated trunk rotation, full range window wiper, sit-ups, curl-ups, crunches, side bends or side crunches, superman, or traditional hyperextension.
Start Doing: Birddog, Palloffs, Chops/Lifts, Loaded Carries, Side Planks, Planks, Front-Loaded movements such as squats, deadlifts, rows.
As always, thanks for reading!