What is the MOST appropriate device to use when immobilizing a patient with a suspected spinal injury?

The most appropriate device for immobilizing a patient with a suspected spinal injury is the long backboard. This device is specifically designed to provide full-body support and immobilization, which is crucial for minimizing movement of the spine during transport. When a spinal injury is suspected, it is essential to keep the patient's spine as stable as possible to prevent any potential exacerbation of the injury.

The long backboard allows the EMTs to secure the patient while maintaining spinal alignment, providing a rigid surface that helps to immobilize not just the spine, but also the head, neck, and other body parts. This universal approach is vital in preventing further injury and facilitating safe transport to a medical facility.

In comparison, other devices like the portable stretcher and standard ambulance stretcher do not provide the same level of immobilization for spinal injuries. Although they are useful for transporting patients, they might not adequately prevent movement of the spine. The short spine board is typically used for specific situations where space is limited or for certain types of extrication but does not offer the full-body support that a long backboard provides in the context of suspected spinal injuries.