Final answer:
The lateral malleolus is the outer ankle bone, formed by the bottom end of the fibula, and plays a crucial role in the stability and function of the ankle joint.
Step-by-step explanation:
The lateral malleolus is the bony prominence located on the lateral (outer) side of the ankle and is formed by the expanded distal end of the fibula. Technically, it assists in the ankle joint's stability by articulating with the talus bone of the foot.
The ankle joint is a complex articulation involving the tibia, fibula, and the tarsal bones of the foot. The lateral malleolus projects down from the fibula and provides a sturdy connection on the lateral side of the joint. This prominence is quite palpable and is often referred to when describing ankle injuries, such as fractures or sprains. Functionally, the lateral malleolus serves as a site for ligament attachment and helps support the weight of the body by forming a stable outer bulwark for the ankle.