The bones that protrude from the top of the foot are seen on the inner and outer sides of the ankle, while the inner protruding bone is called the medial ankle bone and the outer protruding bone is called the lateral ankle bone. Both the outer and inner ankle bones are part of the body’s commissural joint structure, which has a weight-bearing and weight-lifting function. At the same time, they work together with the muscles and ligaments around the ankle joint to maintain the stability of the ankle joint and prevent it from being damaged. Since the outer ankle bone and inner ankle bone are covered with less fat tissue and soft tissue, and the skin is weak, it is easy to be injured by foot sprains in daily life and cause ankle symptoms such as swelling, pain, and difficulty in walking. Under the direct impact of external force, fracture can also occur and cause localized bruising, swelling and other symptoms. It is important to protect your ankles from external impacts and injuries.