Comfortable and best position are different.
The best position to prevent back ache, blade hurting, is to sit at on a chair at a table/desk. keep your back vertical and don't bend the head.
If it's heavily stylus oriented use the console stand provided with Kid Icarus to see in front of you. (I use it for DS too)
But I don't do it often as it's not the most comfortable to sit on a chair for me, I have few positions.
- Sitting position, I take the console in my hands and put them on my legs near the pelvis and bend the head. but it's that position which ends hurting your blades, neck, cervical vertebrae, or your bottom back.
- Sitting position, I take the console in my hands and put the console in front of my head, in hight position, left hand's little finger at the bottom of the console to maintain and stabilize it. (it acts as a console stand)
This is the position I use the most if I can't lay on my bed. but it ends being heavy on the arms, so I switch between this position and the one above.
- My preferred position is laying on my bed, on my back with a pillow behind my blades. I'm almost in a sitting position (between sitting and sleeping position), with legs straight on the bed.
the elbows are laying on the bed, and I'm holding the console in front of my head.
It doesn't have any constrain on the back or the head in this position, but sometime my hands ends numb because of the elbow being on the bed. it might compress the circulation, so I just lift my arms a little and the numbs go away, or I lay on the side a little with the console on the bed.