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Core Knowledge


All You Need to Know to Build Stability


A strong and lean body looks great, but a rock-solid midsection, or pillar, including your hips, core, and shoulders, will boost your performance and significantly reduce your risk for injury. Here’s how to get stable.

Dave Cruz

Shoulder Stability

Anyone who participates in a sport involving hitting or throwing understands the importance of the rotator cuff muscles, but they’re even more important in everyday life. You can think of your hands and arms as carrying the workload for your upper body, but it’s really your shoulders, or at least it should be, that, er, shoulder the load.

The Anatomy of Stable Shoulders

The shoulder “girdle” consists of the humerus (a long bone in your upper arm), scapula (your shoulder blades), and clavicle. It’s engineered for a remarkable range of three-dimensional movement. From the shoulder, you can rotate, press, and pull with your arms. You can raise them out to the side or across the body. And you can rotate your shoulders by holding the elbows in and by moving up and in—or in a 90-degree angle to the torso. Why should you care about all of this? Because it matters a great deal to maintaining perfect posture and staying injury-free.

Poor Posture

It’s our natural instinct is to drop the shoulders forward, especially after long periods of sitting. But if you were to look at a skeleton, you’d notice just the opposite—that the shoulder blades stay back and down.

Most of us don’t realize how hunched over we are from sitting at computers and traveling in cars most days. People tend to think that this affects only the elderly, but that’s not the case. Next time you’re people-watching at a mall or airport, pay attention to the position of their thumbs. If your thumbs rotate inward (and your palms face back behind you), that means your head and shoulders have moved forward.

Why’s this a problem? Aside from Neanderthal-like appearances, the hunched over look makes you significantly more likely to encounter rotator cuff and back problems, which can limit your ability to participate not only in sports, but also the daily activities of life.

Fix Your Shoulders

As people age, they tend to flex forward, as if the chest is caving in. We want to do the opposite, almost as if there’s a fish hook inserted under the sternum, pulling us up. This will allow your shoulders to fall into place and help you stand taller—and look leaner, as a result.

We’re not trying to be military cadets, standing at attention. Instead, think of this as standing or sitting tall in a comfortable position, always elevating your sternum.

The exercises in Core Performance training programs will require you to bring your shoulders back and down, but you’ll want to make it a daily habit. To make lasting change, you’ll actually lengthen your chest muscles and strength the muscles of your upper back.

If you create a habit of bringing your shoulders down (think toward your back pockets), you’ll be amazed at the results. People will find you more confident and think you’ve lost weight and grown taller because you are no longer slouched over.

Core Stability

The middle third of what we call the “pillar” is the core, which consists of the muscles of the abdominals, torso, and lower back. It’s the vital link between shoulder and hip stability, and it includes such muscle groups as the rectus abdominis (your 6-pack muscle), transverses abdominis (your body’s built-in weight belt), internal and external obliques (the muscles that run along the sides of your torso), lats (which wrap around your back and give you the “V” shaped appearance), the erector spinae (along your back) and many small stabilizer muscles between the vertebrae of the spine.

These are the tiny muscles that often get shut off because of a back injury and never become reactivated, causing long-term back problems. These small stabilizer muscles cannot function alone; they must be helped by training the muscles of the core to become strong and stable with the right types of recruitment patterns that will enable them to work in tandem with the shoulder and hips.

Obsessed About Abs

Core training is not just about the abs—abs are less than a third of the equation. Countless books and magazine articles promise great abs, and though many of them have terrific exercises that we believe in, they’re of little use unless done in conjunction with exercises aimed at integrating your shoulders and hips. Instead of just focusing on the abs, you need to build a framework for all movement. The aim isn’t just a well sculpted midsection; it’s a high performance core.

In order to maximize the benefit of your workout, it’s critical to keep your midsection tight not just while training, but all day. Think of your tummy flat against the hip bones. You might try bracing it as if you were about to be punched in the gut. Or you can think about pulling your belly button in towards your spine and away from your belt buckle. This isn’t the same as sucking in your gut and holding your breath. Keep the abdominals tight, but still breathe normally.

The abdominal and lower back muscles work as a team. The point guard is the transverse abdominis, which is the first muscle that’s recruited each time you move. If you can keep that “TA” activated and your abs tight, you’ll be well on your way to more efficient movement, a stronger body and one with less risk of breaking down over time.

Hip Stability

Many injuries are caused by hip tightness and lack of hip stability. Here’s why:

We tend to think that if our ankles, knees or feet hurt, there must be something wrong with those areas. But if we again look at the body as a wheel, the pillar, and more specifically, the pelvis, is the hub of that wheel. The pelvis is in charge of controlling the spokes. You might have the greatest spokes (legs and thighs), but if something goes wrong with the hub, the spokes cannot function.

When your hips are tight and you lack stability in that area, your body can’t recruit the necessary muscles from the pelvic region, and it puts more stress on the other areas, which overcompensate and get injured.

We want to go to the source of that problem and prevent injuries from happening. On either side of the pelvis is a hip “capsule,” where the femur attaches to the pelvis. This along with more than 40 muscles in and around this hip capsule creates the “hip cuff.” This should allow you to rotate your knees in or all the way out, as well as lifting your leg up or back and in every combination. You should be able to lift a leg up and across your body, as if posing for the Heisman Trophy.

Most people get into trouble squatting by using their quadriceps rather than the muscles of the hips to initiate movement. As a result, the knees slide forward, the glutes don’t get involved and there is undue pressure on the knees and back. Our goal is to become more glute-dominant. Watch kids and see how well they squat and stand up. Many of us have lost this movement from sitting too much and being inactive.

Always initiate your squats by pushing your butt back and sinking down all while you bend your knees. Think about sitting back in an imaginary chair, keeping your chest elevated, your shoulders pulled back and down, and your abs tight. When you try to sit with your hips, you’ll create an arch in your lower back, shifting your weight to the middle part of your foot, even a little toward the heel. Feel your glutes and the other muscles of your hip capsule stretch as you lower your body. Squeeze your glutes to stand back up.
If you’re going up steps, squatting to pick something up, or simply standing up, you still want to initiate movement with your hips and squeeze your glutes. This way, pressure is on your hips—where nature intended—not on the knees.

Avoiding Injury

One reason we see so many running-related injuries is because people don’t have the necessary hip stability. Runners have to be able to effectively balance on a single leg and move from the hips. If the hips don’t stabilize, the force created by the pounding of running is stored in the body. That energy is absorbed and stored in the muscles, tendons and joints, leading to overuse injuries.
But if you’re stable in the hips, core and shoulders, the energy transfers through the feet, legs, core, and through the opposite arm, leading to maximum performance. So, by creating a mobile and stabile hip joint, you will store and release energy efficiently, creating optimum movement.

A properly functioning pair of hip capsules is the most powerful thing you have in your body, but it’s the most destructive if it’s locked down. If your hip capsule is locked down, lacking stability or mobility, it’s as if a bone is welded to the pelvis—it’s like having a cast on your hip. To get anything to move, you need to have excessive motion in your back and knees. But the better job you do of creating stability, mobility and strength around the hip, the less potential there is for injury and the far better chance you’ll have of performing well in any activity you do.

Gluteal Amnesia

You know the easiest way to get buns of steel? Use them constantly. Don’t do just one isolated workout. People who have flat, shapeless butts do not use their hips and glutes properly in everyday movement; they just have a couple of saggy bags back there. Some coaches have began to refer to this as "gluteal amnesia" because the glutes have forgotten how to work. You need to wake them up.

Look for every opportunity to lengthen and strengthen your glutes, whether it’s squatting, going up stairs, getting out of a chair or simply walking. It’s the foundation for all movement. Think of life as one big glute workout and you’ll see amazing results. Every time you walk, move and bend, fire (squeeze) those glutes. After all, you’re an athlete in life, and that’s not just when you’re working out. Throughout the day, use your glutes and think about proper posture, with your abs tight and your chest elevated. You’ll look and feel more confident, and you’ll perform better than ever.

Tags: Pillar strength, Stability, Shoulder, Abs, Hip, Torso, Glutes


  1. Verstegen, Mark, and Pete Williams. Core Performance Essentials: the revolutionary nutrition and exercise plan adapted for everyday use. Pennsylvania: Rodale Press, 2006.