This is a pose we see often in yoga classes, and the common misconception is that the legs don't lift away from the mat. When you do lift the legs away, it suddenly becomes a more physical, full-body pose. Another tricky part is learning how to draw the shoulder blades toward each other for an open chest. Once you do that, you take tension out of the upper body, and the weight distribution feels a bit more even in the hands.
I hope this helps - if you have questions about a particular yoga pose, please let me know in the comments below - I'd love to help!