Utthita Parsvakonasana, standing pose, Primary series of ashtanga yoga.
To fold your torso toward the bent leg, activate hip flexors and those of colonna. The foot of the back leg should be well grounded and rotated slightly inward as it helps to bring the heel to land. The co-activation of the gluteus medius and the adductor magnus stabilise the femur and position, shifting the weight to the outside of the foot that moves the rear leg from the front. This action along with the adductor magnus extends flexing column toward the bent leg and simultaneously opens the chest forward and upward. With triceps stretches and extends the elbow. The hand ground serves not only for stability but also to activate, if pushed well to the ground, the serratus anterior and other muscles to rotate the outside shoulder (shoulder external rotators including the infraspinatus and teres minor).The knee must press towards the arm (then outward while the arm is opposed to its action) that is stretched to the ground to prevent the femoral articulation protrude outwards. In this way we activate the so-called “contraction closed loop”, I mean: move the muscle origin rather than its insertion: that we activate the gluteus medius and tensor fascia lata.
Press well the big toe of the hind leg and the little finger activating the arch. The utthita Parsvakonasana is a position where it has the elongation of muscles starting from the foot of the back leg up to the hand of the same side.Try to keep your hips in a neutral position when you step back to get into position. But after the hip of the back leg rotates outwards (behind so to speak) and push it down until you have the angle of the knee of the front leg 90 degrees. Chakra stimolato is Manipura Chakra.