Backboards have their place for spinal immobilization.
Every area has their own protocols for when to Immobilize.
A Vacuum Mattress is basically a flat air tight vessel containing thousand of small plastic/foam beads. When you wrap/apply it around a patient and remove all the air the beads sinter around each other and form a rigid body splint as long as the vacuum is held.
They are much more comfortable, you can put the patient in a position of comfort (on their side etc) and if you can keep the snow out they are very warm. Down side is; If you puncture them they lose integrity, they are a bit of a challenge on a steep surface because they are slippery and so is snow, they are not cheap.
All that said, they are a tool just like a BB. Use proper spinal precautions if a spinal injury is suspected and if all you have is a BB, use that.
Edited by Studebaker Hawk - 2/24/16 at 6:50am