Any poses with an arm bind open the shoulder girdle, and thus, the heart chakra. They can also be more challenging for the core, and in this case, the quads. Bound side angle stretches the groin and hamstrings, too.
Enter the pose from a traditional extended side angle http://thenamastecounsel.com/utthita-parsvakonasana-extended-side-angle-1/. Then, let the top arm drop behind, as the lower arm reaches inside the front leg. Attempt to clasp both hands, and pull the top shoulder back to open up the chest. For those whose shoulders won’t allow them to reach behind the back with both hands, a strap, belt, towel, or even a shirt can be used to imitate the full stretch.
Ashtanga yoga incorporates many binds. Arm binds are a great way to stretch the shoulders, spine, and deepen the twist, thereby adding more compression to the internal organs.
Just like with any other new diet or work out plan, consult a yoga therapist to determine what is best suited for your particular physical and emotional wellbeing.