Vrksasana: The Story of Tree Pose
By Ray Long, MD, FRCSC • August 7th, 2011 • 17477 Views
Step 2 Activate the quadriceps to straighten the standing leg. The gluteus medius automatically contracts when you balance on one leg. You can see from the inset that if the gluteus medius did not activate, the body would shift over and beyond the standing leg and the pelvis would tilt excessively. The bent-leg foot pressing into the thigh stabilizes the standing leg. The tensor fascia lata is a synergist of the gluteus medius in this pose. Visualize this muscle contracting to refine balance and stability. Additionally, the tensor fascia lata works to extend the knee, so it is also a synergist of the quadriceps.
Step 3 Use the gluteus medius and tensor fascia lata of the bent leg to draw the knee out to the side (abduct it). Activate the gluteus maximus to externally rotate the femur. Observe how co-activation of these muscles stabilizes the bent-leg hip.
Step 4 Contract the deep external rotators to open the hips and create space in the front of the pelvis. Notice the gluteus minimus in this pose. This muscle is deep to the gluteus medius and has different functions, depending on whether the hip is flexed, extended, or neutral. In Vrksasana, the standing hip is neutral, so the gluteus minimus works to stabilize the ball of the hip joint in the socket. Also look at the interplay between the gluteus minimus and the deep external rotators illustrated here. This combination of muscles stabilizes the hip of the standing leg.
Step 5 Activate the peroneus longus and brevis muscles on the side of the standing leg to spread the weight across the ball of the foot. Balancing on the standing-leg foot shows a complex interplay among the muscles that evert the foot and press the ball of the foot down, those that invert the foot, and those that flex and extend the ankle. The tibialis posterior balances the eversion force from the peronei and dynamizes the longitudinal foot arch. The muscles of the toes also contribute to stability in the pose.
Summary Connect the various parts of the body, from the foundation formed by the standing foot through to the palms of the hands. Engage the muscles of the ankle and foot to stabilize the foot, the quadriceps to extend the knee, and the abductors (the gluteus medius and tensor fascia lata) to stabilize the pelvis. The pelvis...