In Diagnosis and Treatment of Movement Impairment Syndromes, renowned physical therapist Shirley Sahrmann writes “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….whereas a large % of low back problems occur because the abdominal muscles are not maintaining tight control over the rotation between the pelvis and spine.”
Dynamic stabilization
The biggest and most important role of our core is to provide a stable base of support to allow proper functioning of the upper and lower extremities. All things considered equal, it is the core, which allows all other movement to occur. It stabilizes in order to allow leverage, and control efficient movement in the extremities. With this idea in mind, we could look at the animal kingdom and argue that the giraffe has probably the strongest core of any animal. It has to stabilize and control all the movement of it’s head and legs, which are very far from it’s center of gravity!
A picture is worth....well...not much
One of the biggest misconceptions regarding the core is that we think we can take a picture of it. Magazine covers are a dime a dozen with models showing off six-pack abs, but that tells us nothing about their core strength. I have seen plenty of baseball players hit a ball over 450 feet that do not have six-pack abs….but they sure have plenty of core strength! The only thing a picture of six-pack abs tells us is that someone eats a really clean diet…that’s it! Look at pictures of people in third-world countries...there are plenty of people with six-packs, but it's not because of their core strength either. To effectively gauge someone’s core strength, we need to see how well someone moves because a sloppy core will make every other movement sloppy as well.
The Inner & Outer Unit
Proper functioning of the core really depends on the muscles we cannot see. It is the deep (inner unit) muscles of our abdominal region which have origins on the lumbar vertebrae which are responsible for stabilizing the spine. If you think of your core as a pirate ship, with the mast of the ship representing your spine, the big guy-wires mimic the larger core muscles of the outer unit (the six-pack rectus abdominis, and the erector spinae running posteriorly on either side of our spine). These muscles’ functionality are completely dependent upon the smaller guy-wires stabilizing and providing support (such as the transverse abdominis, obliques, multifidus, diaphragm, and pelvic floor muscles). It is easy to see in this analogy how impactful a muscle imbalance can be, if one of the guy wires is pulling much harder than it’s reciprocal side, the posture of the ship will be altered!
Training Considerations
We are all very familiar with the old-school exercise of a sit up. Many times people might perform a sit up fast or explosive, or some variation of a crunch in the same manner....and it must be working our core because we can feel it right? Picture yourself driving in your car...if you hit a speed-bump at 30 mph, and get a little air time, it would probably be fun right? And I am sure your car will keep running smoothly. But if you consistently hit that speed-bump time after time, day after day, you would probably start to hear some funny noises, some clanking, or squeaking sounds coming from the car the next time you make a turn... So doing a set of sit ups one time might not have any damaging effects, because our body is much more resilient than a car, but repetitive trauma will cause a future breakdown. Take a look at the following picture:
If we can apply Shirley Sahrmann's concept of the way our core functions in everyday activities (it's role is to isometrically stabilize and prevent movement in the spine) our training should be reconsidered to be anti-rotational training, anti-flexion, and anti-extension exercises. The latest research is telling us we must first train the core to prevent flexionSahrmann described the core to work primarily isometrically…it is safe to now say that a proper pushup is a much better exercise for the core than a sit-up is. This approach is quite contrary to the old-school train of thought, but makes sense when we consider the functional role of the core is to stabilize and NOT MOVE in the presence of bodily movement.
Exercise selection must be careful to first focus on developing adequate stabilization of the deep core muscles (inner unit) prior to focusing on the larger outer unit muscles. Perfect execution of the following exercises force the core to resist extension, resist flexion, and resist rotation. All of these exercises should be held isometrically for time, and increase the time to make it more challenging.
Once these exercises are easily performed, it can be a great time to start incorporating chops and lifts into the training program. Chops and lifts might look like an upper body exercise, however when performing the exercise, it is important to keep the core like a statue....not letting the hips move, while the upper extremities are rotating. This creates an extremely high demand for the deep core muscles to stabilize and prevent moving. The other benefit of chops and lifts are the fact that they are diagonal plane exercises, which incorporates all 3 Planes of motion in the shoulders, while increasing mobility of the thoracic spine.
References:
Boyle, M. (2010). Advances in functional training: training techniques for coaches, personal trainers, and athletes. Aptos, CA. On Target Publications.
Chek, P. (2006). The inner unit. Article retreived from www.ptonthenet.com
Cook, G. (2010). Movement: Functional movement systems. Santa Cruz, CA. On Target Publications.
Ellenbecker, T., De Carlo, M., DeRosa, C. (2009). Effective functinal progressions in sport rehabilitation. Champaign, IL. Human Kinetics.
Sahrmann, S. (2001). Diagnosis and treatment of movement impairment syndromes.
Weingroff, C. (2011). Training = rehab Rehab = training: A new language for physical therapists & personal trainers.
