Substantial core strength is needed to obtain the capital "T" position. Straightening the lifted leg and getting it in line with the torso is the first challenge. Also, there is a tendency for the hip of the lifted leg to angle upward into an position in between Warrior III and Half Moon Pose (see below.) The front of the pelvis should be squared toward the floor. The drishti (focal point) at the extended hands also creates more of a challenge than looking straight down at the floor.
4.) Ardha Chandr ā sana (Half Moon Pose): What makes it challenging?Largely, the same challenges that make Warrior III difficult. However, "stacking the hips," i.e. getting the front of the pelvis squared to the wall (not the floor or at a downward angle) requires a high degree of hip flexibility. Hip openers may be necessary to be able to stack the hips without the torque of lifting the top hip up throwing one off balance.
3.) Parivrtta Ardha Chandrāsana (Twisted Half Moon Pose): What makes it challenging?Again, this posture shares challenges with Warrior III and Half Moon. While it's less difficult than Half Moon in that it doesn't require hip stacking, it makes up for it in that twisting motions tend to make staying on balance difficult. This is because one has to remain stable on the standing foot as the torso rotates and if one can't stack one's shoulders the weight distribution may be hard to keep balanced. Also, achieving the drishti (looking at the upper hand) without breaking balance is no easy feat.
2.) Ardha Baddha Padmōttānāsana (Bound Half Lotus Pose):
What makes it challenging?The knees should be next to each other, but the knee of the folded leg wants to be forward and to the outside. Also, one must get the heel aligned on one's centerline (below the navel) so that when one folds the foot is in a position where it can compress into the soft, fleshy tissue rather than being wedged between bones.
1.) Ūrdhva Prasārita Ekapādasana (Standing Split): What makes it challenging?Straightening the lifted leg without throwing oneself off balance is the big challenge. It's possible to put both hands around the support leg ankle, to make it even more challenging, but one must have an exit strategy in case one loses balance.
