Which description fits a contusion?

A contusion is characterized by localized swelling and bruising resulting from a sudden blow or impact to a muscle or soft tissue. This injury occurs when small blood vessels are damaged and leak blood into the surrounding tissue, leading to the characteristic discoloration and swelling. The impact does not necessarily break the skin but can cause significant pain and tenderness in the affected area. This makes the description of a sudden blow causing localized swelling the most accurate representation of a contusion.

In contrast, the other descriptions pertain to different types of injuries. Stretching of muscle fibers typically refers to a strain rather than a contusion. The term "ovular movement of limbs" does not correlate with any specific injury type and is vague. Intense pain following muscle rupture is indicative of a more severe injury, such as a complete tear of muscle fibers, rather than the localized trauma that defines a contusion. Therefore, the first option accurately captures the essence of a contusion injury.