It was invented by Loed and Haederlé, who called it "shell" mattress (matelas coquille in French).

The top of the head must be kept clear (the mattress could retract when pumping out the air and thus compress the spine).

[2] When only three team members are available and there is no scoop stretcher, the following procedure can be used: While the lifting methods can induce a flexing of the spine, this rolling method can be hazardous for several reasons: the risk of a torsion of the spine when rolling, the risk when sliding the casualty on the mattress, the risk of anteversion of the hips (and thus of flexing of the spine) due to the weight of the legs when lifting the mattress to slide the board.

While at ambient air pressure, the beads free to move, but when the mattress has been moulded and the air evacuated, external atmospheric pressure locks the beads in place (jamming) and the mattress becomes rigid.

For this reason the bag is typically bigger than an adult human body (though the same principle may be employed to create an 'instant' cast to stabilise an injured limb).