What is the term for a loss of function resulting from a blow or fall?

The correct term for a loss of function resulting from a blow or fall is concussion. A concussion is a type of traumatic brain injury that occurs when the brain is jolted or shaken within the skull, often due to an external force like a blow to the head or a fall. This impact can lead to a variety of symptoms including confusion, headache, and loss of consciousness, demonstrating a clear loss of normal brain function.

In contrast, a fracture refers specifically to a break in a bone and would not apply to brain function. A contusion is a bruise resulting from an impact that causes bleeding under the skin, typically not involving a loss of function in a significant way. A sprain is an injury to a ligament caused by overstretching or tearing, which affects joint stability and may involve a loss of function, but it does not pertain to the brain, making it less relevant in this context. Thus, the characteristics of a concussion align most closely with the definition provided in the question.