A closed soft-tissue injury characterized by swelling and ecchymosis is called a(n):

A closed soft-tissue injury that is defined by swelling and ecchymosis is accurately described as a contusion. This type of injury results from blunt trauma, where blood vessels under the skin break, leading to localized bleeding which manifests as bruising (ecchymosis). The area may swell due to the inflammation and pooling of blood, and while the skin remains intact, the damage occurs within the tissue layers.

The other options describe different types of injuries. An abrasion refers to a superficial scrape of the skin, typically caused by friction. A hematoma is a collection of blood that accumulates outside of blood vessels, often resulting from a significant injury, and can occur as a result of a contusion but is not synonymous with it. A crush injury occurs when a body part is subjected to a significant compressive force, which can lead to extensive damage to soft tissues and underlying structures, typically resulting in more severe consequences than a simple contusion. Therefore, the presence of swelling and ecchymosis specifically identifies the injury as a contusion.