“Imagine if your arms and legs magically disappeared from the armpits and hips. All the muscles in the region between the armpits and hips are your core.” These were the words of the fitness director who supervised me at a gym I worked at many moons ago. I was selected to teach a small-group fitness class called “core values.” To successfully provide class participants with a beneficial outcome from the exercises conducted in class, I needed to know which muscles fell under her definition of core and how to safely and effectively instruct participants in activating them.
“We don’t just sit around and do crunches throughout the class,” explained my boss. “The idea is to build strength in the muscles that create functional movement in our hips, lower back, and shoulders.”
The description seemed a little extreme and morbid at first. Who wants to think about having their arms and legs removed? However, the description immediately resonated with my knowledge of the human body’s anatomy.
A common understanding of “core” seems to focus on the abdominal muscles. Social media feeds, advertisements on our streaming devices, and pictures of hyper-athletic young athletes on protein and sports drinks at the store display their six-packs. Consumers are more than likely to focus myopically on the chiseled abs of the individuals modeling them. These models have been expertly trained by elite-level fitness coaches, directed on what to eat by a dietitian, and prepared for three months for a shot that displays their midsections so defined and chiseled that they could grate cheese on their abs. Add in the beauty of airbrushing, body makeup, AI images, and Photoshop editing, and you have an image of a human with the midsection of a Greek god.
Sometimes, this image of having Brad Pitt’s six-pack is what the general population perceives as the core. While these fitness models have worked hard to develop a midsection worthy of TV, social media, or health supplement advertisements, that image doesn’t necessarily reflect the core strength’s missing pieces that help the general population be more productive and functional while staving off injuries.
Think of the way a caterpillar moves on the ground. They have little nubby appendages that grab the ground as the segmented portion at the center of their bodies reaches forward to move them, little by little. I would argue that caterpillars have a strong core, using my boss’s description of core muscles. Insects with similar morphology to caterpillars are essentially all core muscles. They don’t necessarily use their arms for much other than creating friction on the ground. Humans have four extremities that are invaluable assets in our lives. Somewhat similar to a caterpillar’s body, our spine has multiple segments composed of muscles, bones, nerves, and, most importantly, the spinal cord, which is one of the most critical assets for innervating our body.
To better appreciate the core muscles that create a significant impact on our productivity and functionality, which aren’t just for a six-pack, it’s worthwhile to look at the anatomy that connects the spine to the hips and the spine to the shoulders. The hip girdle is a collection of bones that attach to the spine and the thigh bones. The spinal column is a collection of the cervical, thoracic, lumbar, and sacral columns. These sections of the spine consist of uniquely shaped bones called vertebrae, which stack on top of one another and provide specific properties of rotation, flexion, and extension. The shoulder girdle is comprised of the clavicle and scapula, which are connected to the thoracic and cervical spine by ligaments, tendons, and muscles.
While there is a vast network of muscles that can fill the pages of an anatomy course guideline, the few muscles that serve as effective core-strengthening movements we teach our personal training clients start at the hips, abdomen, and shoulder blades. The muscles surrounding the hip joints are among the strongest in the body and serve as structural reinforcement at the body’s center. The glutes are among the simplest muscles to identify as hip muscles and are a safe, efficient place to start when focusing on reinforcing hip strength. The muscles of scapular stabilization, which surround the shoulder blades and shoulder joint, help maintain upright posture when standing and sitting. Larger muscles of the shoulder blade include the trapezius, latissimus dorsi, and teres muscles. A multitude of muscles reside along the front, back, and sides of the spine, including the psoas and erector spinae.
The human body is complex. A strong, durable, and resilient core undoubtedly reinforces people’s ability to live a highly functional, productive, and enjoyable life. Perhaps we can take some time to educate ourselves on the different core muscle groups and specifically target the ones that truly make up the core of the body.
Sean McCawley, the founder and owner of Napa Tenacious Fitness in Napa, CA, welcomes questions and comments. Reach him at 707-287-2727, napatenacious@gmail.com, or visit the website napatenaciousfitness.com.