Eagle is interesting from a number of angles. As you grow more familiar with it physically, certain philosophical principles begin to emerge.
The physical process of the Eagle Pose is straightforward. Balancing on one foot, the yogi wraps the free leg around the stable. The yogi also twists his or her arms around each other and has them meet at the palms. The spine is kept as straight as possible, and the weight of the body is maneuvered to fall over the one stable foot. For more thorough instructions on how to achieve the Eagle pose, visit here.
The shoulder stretch in Eagle draws attention to the difference between the parts of the shoulder. The arm on top primarily stretches the side of the shoulder- the ball of muscle that allows the arms to rise perpendicular to the body. The arm on bottom primarily stretches the lower neck- the flesh between the shoulder and throat that raises the shoulders to the ears.
One of the pitfalls of the shoulder stretch is to tense the shoulders or neck. If you are doing this, you must be constantly vigilant that there is no stiffness in your arms and that you are exerting no unnecessary force.
Balancing in Eagle is fairly simple. Pressure ought to be applied uniformly across the foot, and the eyes ought to be open and fixed. With these two guidelines in mind, one can find balance in Eagle swiftly and subconsciously.
Eagle draws attention to a few bodily topics, the similarity and distinction of limbs amongst them. The arms function identically to the legs, but within each pair a dominant and submissive partner exist. Moreover, the dominant below (say, left) corresponds to the submissive above (right.) By having the distinct limbs perform identical functions, their individual nature blurs and the body becomes more unified in the mind.
Also of importance to understanding Eagle is the upwardly thrusting energy of the pose. The grounded leg is necessarily flexed and burning. This well of energy is directed upwards by the upright spine and drawn upwards by the stretching shoulders. Rodney Yee described the sensation of Eagle pose as “flying on the pedestal of one leg,” and once familiar with the pose this definitely rings true.
Becoming comfortable with the pose gives a gradual sense of release. Several large muscles are targeted for stretching, so just entering the pose makes one feel surrounded by tightness. However, as the muscles loosen the sense of stricture and containment give way to the bubbling energy of the powerfully grounded lower leg.
Eagle is a pose that is eternally useful. In early stages of development it trains several large muscle groups to work in a yogic way, and in later stages it is a template for reflection on the nature of the body.