VRKSASANA (Tree Pose)
Key Structures
Lower leg, foot, arch, abductors, and external rotators of the standing leg; external and internal obliques, to stabilize torso to pelvis.
Joint and Limb Actions
Neutral spine, level pelvis. Standing leg: hip neutral extension, internal rotation, adduction; knee extension (not locked). Lifted leg: hip flexion, external rotation, abduction; knee flexion; tibia external rotation; ankle dorsiflexion (pressed against the adductors of the standing leg); foot pronation
Working
Lifted leg: Iliacus and psoas major, all external rotators and extensors - gluteus maximus, posterior fibers of gluteus medius and minimus, piriformis, adductor magnus (extensor portion), obturator internus and externus, gemelli, quadratus femoris.
Standing leg: Piriformis, tensor fascia lata, gluteus medius and minimus, gluteus maximus (extensor portion).
Standing foot: Intrinsic muscles of the foot, muscles of the ankle and lower leg.
Lengthening
Lifted leg: Pectineus, adductor longus and brevis, gracilis
Standing leg: Gluteus medius and minimus, piriformis (working eccentrically).
Notes
The adductors lengthen to get into position; they may have some role in holding the leg in place by pressing the foot into the inside of the standing leg. Misusing the pectineus to hold the leg in place creates flexion at the hip, tilting the pelvis and rotating the leg inward.
Abductors on the standing leg are working eccentrically; if they are weak or tight, the hip of the lifted leg will "hike up," or the rotators will try to stabilize the pelvis and the pelvis will rotate open.
Breathing
Compared to tree pose with arms elevated, the upper body is freer to participate in respiratory movements in this pose. With the arms held in namaste, and the raised leg braced against the adductors of the standing leg, the attention and center of gravity are drawn inward and downward.
VRKSASANA VARIATION - Arms Elevated
Joint Actions
Neutral spine; scapula upward rotation, abduction, elevation, glenohumeral external rotation, abduction; elbow extension; forearm pronation (if the upper arm is externally rotated).
Working
Infraspinatus, teres minor, deltoids, supraspinatus, long head biceps, serratus anterior (supported by the upper fibers of the trapezius), triceps with anconeus to extend elbows.
Lengthening
Latissimus dorsi, teres major, long head triceps.
Notes
Overuse of the latissimus dorsi to "pull shoulders down and back" interferes with the elevation of the scapulae; it can create impingement on the acromion of the biceps tendon and supraspinatus. The rib cage can also be pushed forward from a restriction of the latissimus.
Breathing
Because of the stabilizing action of the muscles that keep the arms overhead, the thoracic movements of the breath encounter more resistance in this position. In addition, the higher center of gravity will tend to produce a stronger stabilizing action in the abdominal muscles. Taken together, these factors combine to reduce the overall excursion of the diaphragm; therefore, quiet, efficient breathing is the most appropriate pattern. Breaths that are too deep will destabilize the posture.
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