A “six pack” does not necessarily mean a strong core. This article describes how to develop mobility and stability for strength.

The five steps of recovery after surgery are: reduce and as soon as possible eliminate swelling, restore range of motion, retrain stability in the joint, establish strength and last but not least, train for power. Those same principles with the exception of swelling (since it typically is not present with chronic pain) apply to anyone who is or has been in pain not related to trauma or surgery. Unfortunately the simple rule of establishing mobility and stability around a joint prior to adding strength to an exercise or rehabilitation routine is an often forgotten principle that results in either temporary pain relief or no pain relief at all.


Mobility around a joint is a prerequisite for any rehabilitation or training program and is often overlooked or addressed by static stretching, which may or may not solve the “lack of mobility” problem. For example, if there is a lack of mobility in the shoulder, the traditional stretching of the pectoral muscles or other muscles around the girdle will not be sufficient. Movement at the shoulder joint is complex and relates to several joints actually: acromioclavicular, sternoclavicular, scapulohumeral, scapulothoracic and is also dependent on the mobility of the thoracic spine itself. One can see that if mobility around any of these joints is compromised a program that does not attempt to uncover the dysfunction will not be adequate to correct the problem. Therefore when in doubt always choose movements that are more complex and address multiple joints. My favorites to aid in shoulder joint mobility are the “carpet angel” and “butterfly.” To perform these two exercises a foam roller is needed.


Carpet Angel: lay on the foam roller placing it along the spine. Head is resting on the foam roller and the feet are hip width apart and knees bent. For the carpet angel place arms next to the body, palms facing up and with an inhale draw an angel’s wings on the carpet just like it would be done on the snow. With an exhalation bring the arms back down and repeat for five minutes.Butterfly: The body remains in the same position as for the carpet angels, but the fingers are interlaced behind the head. With an inhale push elbows apart toward the floor and with an exhalation bring elbows together. Repeat for five minutes.

When it comes to muscles in the body we can generally classify them as stabilizers or movers. Stabilizers or tonic muscles are typically smaller, slow twitch (fatigue resistant) by design and are located closer to the joint. Movers or phasic muscles are typically “beefier”, they can offer a quick physiologic response but fatigue more easily. Because these two basic sets of muscles have different functions they have to be trained differently. Believe it or not, a “six pack” does not necessarily mean a strong core. True, rectus abdominis, the “six pack” muscle, is in the general location of the “core” but its primary role is movement and not stabilization. Stabilization is the job of the “core”, which we have three sets: shoulder, trunk and hip. 

For example, at the shoulder, the rotator cuff stabilizes the glenohumeral joint so that the bigger deltoid muscle can create movement. At the hip, the deep muscles close to the joint create stability so that any single leg stance motion can occur (such as in walking, running or kicking). The transverse abdominis, one of the trunk core muscles, provides stability around the pelvis, which is needed in order to move the axial skeleton (limbs).
In other words, the brain needs to know that the joint is stable before it will allow the movement. Hence, in rehabilitation or training, the muscular system should not be addressed without including the nervous system. Strong muscles that do not fire when they are supposed to are like a computer without the software. The nervous system is the software that dictates the quality of muscle performance. Training the stabilizing muscles by doing static exercise like a plank or a concentric exercise such as a crunch is inadequate. Remember, the stabilizer’s job is to stabilize and to enable movement. To train a stabilizer, the stability exercise with movement needs to occur, along the line with the so-called specificity principle: train the muscle for what it needs to do. When thinking about training “core”, in this case “trunk” core, try the exercises in the box below.


A. Position your body in a pike on the ball with only your toes on the ball and the ball should be fully inflated. The instability of the ball will recruit the core musculature and the movement of the lower extremity will provide the realistic environment that the neuromuscular system needs to learn.

B. A single leg dead lift doing a push press using a kettle bell in the opposite hand will recruit the core to protect the body from tipping over to the weighted side and the movement (dead lift and push press) will provide the specific environment.


Proper rehabilitation and training are complex. When looking for a professional to help you reach the next level, be picky and demand explanation for why and how. Every exercise should have a purpose and every purpose should be to get the best quality of movement with minimal or no risk for injury.


Written by Coach Martina Young PT, DPT. For further discussion or to find out which muscles compose the “core” contact coach Martina

Contact Martina

Right Here!