The Importance of Shoulder Mobility and Scapular Stability
Posted May 20 2010 10:36am
If you’ve been following my series on joint mobility you’ll know that I’ve already covered how to improve and maintain joint mobility for the hips , thoracic spine , and ankles and wrists . Today and tomorrow I’ll be going over the shoulder. The shoulder is a tricky joint because it has to provide adequate stability while maintaining full mobility to prevent injury and maximize function and performance. If you look at yourself in the mirror and wave your arms around, you’ll see what I mean. If that doesn’t work, watch a swimmer, preferably one doing the IM, and watch the incredible range of motion in those shoulders. That’s what the human body is capable of.
Know what you’re looking for and you should be able to count ten different types of shoulder articulations. Ten! Contrast that with the hips ( eight ), the ankles ( two ), the wrists ( four ), or the spine ( five ), and the shoulder is clearly the most complicated joint with the greatest range of motion. Because “with great power comes great responsibility,” the shoulder is also perhaps the joint most vulnerable to injury. You can do a whole lot with a well-functioning shoulder joint, but you can also really mess yourself up and curtail your activity level for a long time if you get haphazard with its maintenance. Take it from a guy who messed his shoulder up more than once: shoulder health is absolutely required for an active, enriched life. And if you plan on attaining any sort of athletic competency on any level, you need good shoulders.
A person’s shoulder joint is composed of the clavicle (collar bone), the scapula (shoulder blades), and the humerus (upper arm bone), along with two joints – the acromioclavicular, or AC joint; and the glenohumeral joint. AC joints exist between the clavicle and the scapula, whereas the glenohumeral joint is the classic ball-and-socket joint responsible for basic arm rotations and hinging. All these bones and joints are in turn supported by the surrounding musculature.
The surrounding musculature is extensive. You’ve got the big boys, like the rear, middle, and anterior deltoids or the trapezius, that get all the credit. They’re the ones that pop out and look great in tank tops. Important? Yes. But there are more important ones, I’d argue. Because for all that mobility and all that muscle mass to work correctly, you need stability. You need a base, something to work from.
This concept isn’t new, and it’s certainly not unique to the human shoulder joint. The entire body’s continuum of joints is governed by this “law.” Mobility-centric joints, like the hips, thoracic spine, and ankles, are connected to stability-centric joints, like the knees and lumbar spine. Each requires the next in line to function correctly and smoothly.
For the mobile shoulder joints to stay mobile and healthy, they rely almost entirely on the proper function of the scapula. Yes, the true key to shoulder mobility is scapular stability. You gotta have strong shoulder blades. You need a foundation.
While doing the bench press, that infamous destroyer of rotator cuffs, a trainee must tighten his scapula to create a “shelf” to lay against the bench. A trainee must also maintain that shelf throughout the set, even (especially) when pressing up. This is scapular retraction, and benching without it – with a loose, rounded back on the press up – will eventually kill your shoulders. It certainly knocked mine out for a good couple of months the most recent (and last) time I tried to max out my bench.
Any overhead work, whether it’s pressing a barbell, lifting a growing child, or moving luggage into the overhead bin on an airplane, requires scapular elevation to help the acromion clear the rotator cuff. It moves, ideally, smoothly, but if you’ve got poor scapular function (say, from kyphosis, or poor thoracic mobility), the upward rotation is halted, and impingement syndrome can result.
Back squats work best with a close grip and strong scapular retraction in order to urge the rest of the torso to stiffen and create that “shelf” for the bar to lie on. Try doing back squats with a wide grip and lax shoulder blades to see what I mean. Actually, don’t; it’ll just hurt your shoulders.
Rowing (machine, boat, or barbell) is all about scapular retraction. You’re not just going to yank on a cable or work a paddle by flailing your arms wildly. Well, you could, but you’d injure yourself. Setting your shoulder blades back and keeping them tight creates a safe, linear path for your primary rowing muscles to travel.
Pull-ups and chin-ups are all about scapular stability, very similar to the rows.
The shoulders figure into every upper body exercise. If your arms are moving, that movement is occurring along the joints that comprise the shoulder. Bench presses, dips, overhead presses, and anything else involving your arms depend on healthy shoulders and good scapular function. Tomorrow, I’ll explain more about the scapula, how to target its supporting musculature, and how it all figures into overall shoulder health and mobility.