Final answer:
The torso is secured last when using a short spine immobilization device. This device is used to stabilize the spine and reduce movement in case of suspected spinal injury.
Step-by-step explanation:
When using a short spine immobilization device, the torso is secured last. The short spine immobilization device is used to stabilize the spine and reduce movement in case of suspected spinal injury. The device is applied starting with the head, then the upper limbs, and finally the torso. Securing the torso last ensures that the entire spine is adequately supported.