Our ability to reach overhead in our warrior poses and to use our arms to lower into our chatarunga dahndasana, also known as Four-Limbed Staff Pose or Low Plank, illustrates the complex demands we put on our shoulders in yoga.
The shoulder is the most mobile joint in the body and is designed for mobility at the expense of stability. The joint’s mobility gives you a wide range-of-motion, such as when you reach overhead or behind your back. However, this design sacrifices stability and makes the shoulder more vulnerable to injury. Where other joints use bony congruency to limit the amount of motion available in the joint, the shoulder’s bony alignment is like a golf ball on a tee. Proper alignment and muscle recruitment are key to keeping our shoulders injury free.
Joints of The Shoulder Complex
When you think of the shoulder, normally the ball and socket come to mind. The shoulder is actually a complex of joints that work together to keep the stability and mobility balance. In addition to the ball and socket joint, the other components of the shoulder complex also include: the collarbone where it meets the breast bone, the shoulder blade where it meets the collarbone, and the shoulder blade resting on the rib cage. When we reach overhead, proper movement at each joint in the shoulder is key to increased motion while maintaining some stablity.
Getting Into The Scapulothoracic-Glenohumeral Rhythm (The ST-GH Rhythm)
The ST-GH rhythm is really a fancy way of describing how the joints in the shoulder complex work together to allow you to reach overhead. For every bit of motion at the ball and socket, there is also motion in the shoulder blade. When you reach overhead, your shoulder blade rotates and lifts, too. This is what ensures that the socket follows the ball and keeps the bones in line with each other.
We use our shoulders to give us a lot of overhead reach AND we use our shoulders to hold our body weight when we are on our hands. What do we do when we combine those actions, when we lift our arms overhead AND put weight down through our arms?
Downward Facing Dog is a great example of this.
Although often taught as a beginner pose, Downward Facing Dog is quite complex. When we are in this pose and bearing weight through our arms while they are overhead, the key is to be sure we have allowed the ST-GH rhythm to do its job. We need to be sure we have allowed the shoulder blades to rotate away from each other and toward our hands. Not only does this give us more overhead motion, it also ensures that the socket is following the ball and the shoulder is strong and stable.
You can experience this motion standing with your arms elevated overhead.
Stand in front of a wall and reach your arms overhead, placing your hands on the wall just as you would in downward facing dog. Your palms should be flat on the wall without bearing weight through them. Slightly drop your shoulder from your ears. Now, leading with the pinky side of your hands and arms, slide your hands further up the wall. Did you notice where this motion came from? If you really lead the motion from the pinky side of your hand and arm, without shrugging your shoulders, you should feel this reach coming right out of the armpit.
You added reach by rotating the shoulder blades toward your hands. Now, if you hold that position for any length of time you will notice how active that pose really can be. From the outside, someone may not realize how hard you are working to keep that reach but on the inside you can feel the activation in the armpit and around the shoulder blades. That activation is keeping your shoulders safe.
Now, bring this to the ground. Begin on your hands and knees. Curl your toes under and lift your hips and knees into Downward Facing Dog. Just as when you were standing at the wall, your palms are flat with your arms elevated overhead. Slightly drop your shoulders from your ears. Now, since your hands are planted and can’t slide like they did up the wall, the motion will be in the torso. So as you lengthen again from the pinky side of your arm, from the armpit, and you “push the floor away” it will feel like your ribs and torso slide toward your hips. Just like at the wall, you will feel the activation of the armpit muscles and the muscles around the shoulder blades. From the outside, it looks pretty relaxing. From the inside you are working to keep the action of “pushing the floor away” to allow the shoulder blades to spread toward your hands and give you more length.
Rather than collapsing into your downward facing dog, you can make this pose quite active and protect your shoulders.