How is a ligament defined in relation to a sprain?

A ligament is defined as a band of connective tissue that connects bone to bone, playing a crucial role in stabilizing joints and providing support throughout the musculoskeletal system. When discussing sprains, which are injuries that occur when a ligament is overstretched or torn, understanding the function of ligaments is essential. These tissues are key in maintaining joint integrity, and any damage to them can lead to pain, swelling, and instability in the affected area.

In contrast, the other options describe different components of the body that do not pertain to the definition of a ligament. For instance, a connection between muscles refers to tendons, which attach muscles to bones. A liquid that lubricates joints refers to synovial fluid, which is found in the joint capsule and aids in reducing friction during movement. Lastly, a type of muscle tissue does not relate to ligaments at all, as ligaments are not muscle tissue but rather a distinct form of connective tissue.