Whenever I announce that we're going to work on our arms in Gomukhasana (Cow Face Pose), my students look at me with reluctance—and reach for their yoga belts. Behind their resigned determination, I suspect they're wondering, What makes this pose so challenging? Why is it so hard to clasp my hands behind my back? I work on my shoulder flexibility often, so why doesn't this pose get any easier?
The simple answer is tight shoulder muscles. The more complicated explanation is that Gomukhasana requires shoulders to move into positions they never assume in daily life. They're not even visited very often in other yoga poses. In Gomukhasana the "up" arm moves into full shoulder flexion with external rotation and full elbow flexion. The "down" arm moves into full shoulder internal rotation with extension.
If that description thoroughly confused you, you'll understand why you need to learn the anatomical principles of flexion and extension, as well as internal and external rotation, before working on your limitations in Gomukhasana. Start by standing in Tadasana (Mountain Pose) with your arms by your sides. Bring your right arm forward and up overhead. When you do this action, you're flexing your right shoulder. With the shoulder in flexion, bend (flex) the elbow, so that your palm touches your upper back, with your fingers pointing toward the floor. Next, reach your left arm behind you, creating extension in your left shoulder. Bend your left elbow and slide your forearm up your back. If you can, reach up between the shoulder blades to grasp the right fingers, hand, or wrist.
Now, to understand the concept of rotation, return to Tadasana with your arms by your sides and palms facing your thighs. Rotate your right arm so the palm faces forward; this is external rotation of the shoulder. Hold this rotation and flex your shoulder to 90 degrees (your arm will be parallel to the floor with palm up). Continue to hold this external rotation and lift your arm overhead into full flexion. If you've managed to hold the external rotation, your palm will spiral toward the wall behind you and your elbow callus and triceps brachii muscle (on the back of the upper arm) will be facing straight ahead, not out to the side. Next, keeping your left arm by your side, rotate it so your palm faces backward and keep rotating until the palm faces out to the side, with your little finger forward. This is internal rotation of the shoulder. Bend the left elbow and bring your forearm and hand around and up your back to clasp your right hand, fingers, or wrist.
Trouble Spot No. 1
Now that you know the joint positions and terminology and the way your shoulders are supposed to move in Gomukhasana, let's see what's preventing you from making the clasp and what you can do about it. As with any other joint, moving your shoulder in one direction can be difficult because of tightness in the muscles that move it in the opposite direction. In the case of the "up" arm, moving your shoulder into full flexion with external rotation can be limited by tightness in the muscles performing extension and internal rotation. These are the latissimus dorsi (the broad sheet of muscle that originates in the low and midback and sweeps up and across the rib cage and through the armpit to attach to the upper humerus, or upper arm bone) and the pectoralis major (the major muscle covering the chest, originating on the collarbone and breastbone and also attaching to the upper humerus). These strong muscles might be tight and short from strengthening activities like chin-ups or rowing, or from a rounded posture or a lack of stretching. You can stretch them by lying in a supported backbend—over a rolled blanket, a therapy ball, or a block placed beneath the upper back—and relaxing for a few minutes with your arms reaching overhead. Be sure to hold the external rotation of the shoulders in these stretches, with palms parallel and triceps facing forward.