Final answer:
An injury to the neck should be assumed to have caused a spinal injury due to the presence of the spinal cord within the vertebral column and the neck's crucial role in bodily functions.
Step-by-step explanation:
Any injury to the neck should automatically be assumed to have caused spinal injury. The vertebral column surrounds and protects the spinal cord and provides support for the head. The neck, being a part of the vertebral column, contains the spinal cord which, when injured, can lead to serious conditions like paraplegia or hemiplegia. The neck's complex muscles and vertebrae also have a significant mechanical impact on the rest of the body, making it crucial to assume spinal injury when the neck is harmed.