Which of the following defines a sprain?

A sprain is specifically defined as an injury to a ligament that occurs when the ligament is overstretched or torn. Ligaments are tough, fibrous connective tissues that connect bones to other bones at joints, providing stability and support. When a sprain occurs, it typically involves the stretching or tearing of these ligaments, often due to a sudden twist or impact that forces a joint beyond its normal range of motion. This can lead to pain, swelling, and instability in the affected joint.

In contrast, injuries to muscles are classified as strains, while injuries to tendons, which connect muscles to bones, also are distinct from sprains. Fractures, on the other hand, refer to breaks in the bone structure itself. Thus, the unique characteristics and causes of a sprain clearly differentiate it from these other types of injuries.