Better known as the shin or shin bone, the tibia is the larger and stronger of the two lower leg bones. Together with the femur, it forms the knee joint. It also forms the ankle joint with the fibula and tarsal bones. Though both the tibia and the fibula occupy a similar area, the tibia sits closer to the middle and center of the leg. Additionally, the tibia acts as the anchor point for many powerful muscles, tendons, and ligaments that help perform activities such as walking and running.


1. Composition

The tibia is a long bone, a classification that describes its long and narrow shape. All long bones are hollow in the middle with ends that contain spongy bone consisting of many small columns that help protect the bones from outside stress and pressure. Holes between the columns contain red bone marrow that produces red blood cells. Within the hollow section or the medullary cavity is a layer of yellow bone marrow that can store energy for the body. The thick substance that surrounds this layer is compact bone containing a matrix of hard calcium mineral and collagen protein that provides strength and flexibility.

long bone cross section 7activestudio / Getty Images


This site offers information designed for educational purposes only. You should not rely on any information on this site as a substitute for professional medical advice, diagnosis, treatment, or as a substitute for, professional counseling care, advice, diagnosis, or treatment. If you have any concerns or questions about your health, you should always consult with a physician or other healthcare professional.