It is important not to collapse into this pose. The pelvic floor, hamstrings, and gluteals should act eccentrically to distribute the weight created by the force of gravity through the whole base of the pose rather than drop right into the hamstring attachment or knee joint.
As with all poses, and more so with complex ones, a wide variety of experiences are available, depending on each person’s strength, balance, and range of motion.
This pose is categorized as a kneeling pose because that is the starting position, but the base of support is not actually kneeling. This asana has a unique base of support: the back surface of the front leg and the front surface of the back leg. This same base, with the knee joints extended, would almost be hanumanasana.
Even though the front leg is externally rotated, this pose still requires a great deal of length in muscles of external rotation such as the piriformis, obturator internus, and superior and inferior gemellus. This is because these muscles are also hip extensors and abductors, and the actions in the front leg are hip flexion and adduction—the more adducted the front leg is, the more sensation will probably be felt in those muscles.
When the knee is more extended in the front leg (toward 90 degrees of flexion), the rotation at the hip is greatly intensified. This action puts more pressure into the knee, especially if there is restriction in the hip joint, and the knee is much more vulnerable to twisting forces when at 90 degrees. The action in the feet and ankles can help to stabilize and protect the knee.