The inner side of the lower leg bone, also known as the tibia. In fact, the tibia is the standard designation for this part of the leg. Located on the inside of the calf, the tibia is the main weight-bearing bone of the lower leg, is relatively thick, and is divided into two ends. The two ends of the body refer to the center diaphysis, as well as the upper and lower epiphyses. The upper diaphysis is divided into the medial and lateral condyles, which are opposite the femur and form the main part of the knee joint. The lower diaphysis is primarily opposite the talus and forms the tibio-talus joint below. There is also a peroneal articular surface on its lateral side, which articulates with the head of the fibula. The body of the tibia is trigonous, and its anterior and medial surfaces are immediately subcutaneous and palpable on the surface of the body. The medial surface of the lower end of the tibia bulges out and is called the medial malleolus. The outer side has a triangular fibular notch, which is closely attached to the fibula.