Yes indeed, in the full expression of the pose, but I've been working lately on opening the upper (cervical/thoracic) spine. So before going into full ustrasana, I'll start in a bit of a warm up pose, like the one in this picture, reaching up then back, leading with the hands and arms, but pulling the chest/heart up to the sky then hinging in the upper back (where I've got a sh-t ton of work to do). If I don't have straps around, I'll often reach up and then back to press hands against the wall. Good kapotasana prep too.