One reason why arm balances can be very challenging is that they require both strength and flexibility.
A great place to start your journey towards arm balances might be to create strength in the upper body and the abdominal muscles, never the less, having the capacity to twist and extend your body is going to make it so much more easy.
Any of the sitting twists, like Ardha Matsyendrasana, can help you to build intercostal space, body awareness and most important rotational flexibility in your spine something that is needed for asanas like Parsva Bakasana (Side Crane Pose).
If you don’t have yet the strength to lift your self up, perhaps foccusing in asanas like plank pose or dolphin pose, can be a place to spend some good hours in order to establish a solid foundation.
Bhavanga Yoga 