Posture and the Importance of the Core

When our parents told us to “stand up straight,” they were teaching us a valuable lesson in body mechanics. Our Center of gravity (COG) in the human body is located a couple of inches below the belly button and is slightly posterior. It is vital because it is the balance point of the body. Think of the center of gravity as the fulcrum of a teeter tooter. If there are irregular forces on the fulcrum, the lever arm or force must change to create balance. As in the example of the teeter tooter, if someone is heavier, they move toward the fulcrum to balance the weight, or the lighter person moves toward the end of the teeter tooter. Notice in the picture below that the points are distributed to balance along the COG line.

If we think of the body as a series of lever arms coming from the COG, we can use the equation of Work= Force x Distance to describe; a more extended lever arm requires more work or counter force than a shorter lever arm the same weight to keep in balance. Therefore, the further the structure is from the COG, the more rotational force or torque it creates on the COG and the joint in malalignment.

Postural malalignment causes a breakdown in our body and, in most cases, pain. The reason being it changes the distance and balance of the body from COG. In turn, structures throughout the body are stressed more than they were designed to be, and breakdown occurs. For example, a plastic chair holding a 150lb person will hold a 200lb person. Although, over time, the excess stress is going to cause cracks in the chair, and eventually, the chair will break.

The picture above shows the human body in perfect balance with the COG. Notice that the shoulders are behind the mastoid process while the ears are in alignment. The hips are forward to the COG, while the knee joint is neutral and the ankle joint being slightly posterior. For example, we will talk about the most common postural malalignment I see forward head/shoulders. Let’s use the physics we learned to evaluate the excess stress on the body. In the picture above, the head is the farthest vertical height (long lever arm) away from the COG and is in line with the COG. Due to it being aligned with the COG, it creates no torque on the COG if kept in proper posture. When the head hangs forward, there can be an anterior torque up to 3x the head's weight. Then add rounded shoulders in conjunction, now we have created a significant anterior torque on the COG. Our low back is posterior to the COG and has to compensate for the excess force created from incorrect posture. Some other common anterior torques are having a belly or lifting something heavy. No wonder 80% of the population will have low back pain at some point in their life. “Stand up straight” now packs more punch than anticipated at a young age!

As you can see, when we use our bodies outside proper alignment, we create torque on our COG, and compensation occurs throughout the body. Our COG is the foundation of every movement, and without its balance, we start every movement without foundation. Due to the COG being the foundation of every action, it is essential to have a strong core. The core muscles are a girdle of muscles around the COG, creating a greater base of support. The core muscles are the gluteus maximum, latissimus dorsi, erector spine, transverse abdominals, rectus abdominal, and internal/external obliques.

Some core exercises that create bang for their buck are squats, planks, bridges, lumbar extension. Always check with a doctor before starting an exercise program if you have any injuries if these exercises are okay to do.

Squats:

Plank:

Side plank:

Bridges:

Swimmers:

Now that you learned about proper posture and how to train the core. I hope that you can use the information to better your health and wellness.