Tibia: What to Know

Medically Reviewed by Dany Paul Baby, MD on September 01, 2022
Written by Cheryl Whitten
5 min read

The tibia is one of your leg bones. Some tibia conditions commonly affect kids and can cause leg pain or trouble walking.  

The tibia, also called the shin bone, is one of the two bones in your lower leg. It’s the second-longest bone in your body after your thigh bone. The tibia is paired with a shorter leg bone called the fibula, and they’re connected with an interosseous membrane. This membrane is a sheet of connective tissue that acts as a type of joint. 

Your bones are living organs with a few important functions. They provide structure and shape to your body, help you move, and store minerals like calcium and bone marrow. 

There are two types of bone marrow: red marrow, which has stem cells that become red or white blood cells and platelets, and yellow marrow, which becomes fat, cartilage, or bone cells. The tibia is a long bone that contains mostly yellow marrow, but the ends also contain some red marrow. 

Your tibia has a few other specific functions, too.

Bears weight. As the more prominent bone in your lower leg, your tibia is the weight-bearing bone. It’s the stronger of your lower leg bones, supporting the weight of your body as you move and stand. It also stabilizes your knee and ankle joints with the help of the fibula. 

Muscle attachment. The tibia also serves as a point of attachment for 11 muscles, as well as tendons and ligaments that help you extend and flex your knee joint and move your ankle joint. 

The tibia is in your lower leg between your knee and your ankle. While the slender fibula bone is on the outside, or lateral side, of your lower leg, the tibia is oriented toward the middle (or, medial) part of your lower leg.

There are several tibia parts, including blood vessels and nerves that supply nutrients and signals to the bone. Other tibia structure includes:

Proximal aspect. The proximal part of your tibia is the upper end that connects with your femur. It has a rounded head with a medial condyle and lateral condyle (or, middle and outer knob). Here, medial means its position is closest to the middle of your body. 

The upper end has a flat head with an intercondylar eminence between the two knobs. That’s a raised area where two ligaments attach. 

Tibia shaft. The shaft is the long part of the bone that bears your weight. It has an anterior border you can feel just under your skin on your lower leg. The shaft also has a posterior or back surface and a soleal line where muscles attach to the back of your leg. 

Distal aspect. The distal aspect of your tibia is the lower end that connects with your ankle. It has a medial malleolus, which forms a large bony bump on the inside of your ankle. It’s sometimes called the little hammer. 

The fibular notch is on the outside lower part of your tibia. This is a wide groove that connects with the bottom of the fibula and forms a joint. 

While your tibia is one of your strongest bones, it’s not unbreakable. Some signs and symptoms of damage can include:

Lots of conditions can affect your tibia bone. Some of the most common include:

Tibia injuries. Tibia fractures (or, broken tibia bones), are one of the most common injuries of the lower limbs in children. A fracture can be a low-energy break caused by falling or twisting your leg or a high-energy break caused by extreme force, like a fall from heights or a car accident. 

Osgood-Schlatter disease. This disease often causes knee pain, occurring because of irritation of the growth plate at the top of your shin bone. The tendon that connects the kneecap to the tibia pulls on the growth plate and causes pain during activity and sports. This disease affects kids during puberty and goes away on its own without lasting effects. 

Blount disease. This condition also affects the growth plate at the top of the tibia in children. It happens when extra weight puts pressure on the growth plate and stops the bone from growing normally. The inside slows down, but the outside keeps growing, which causes the tibia to bow outward instead of growing straight. 

Paget’s disease of bone. Paget’s disease of the bone happens when your bones repair themselves at a faster rate than normal. Your bones thus become soft or too large, which leads to bending and weakness. This mostly affects older people. 

Osteoporosis. Your bones continually break down and rebuild. Osteoporosis happens when your bones can’t keep up with the loss of old bone, which causes weak and brittle bones. They become so brittle that even mild stress can lead to a broken bone. Anyone can get osteoporosis, but older white and Asian women have a higher risk. 

Shin splints. Also known as tibial stress syndrome, shin splints are the pain you get on the front of your lower legs from exercise. This happens when you repeatedly stress your shin bone from running, after you increase exercise intensity, or because of flat feet or high arches.  

Your tibiae are important for movement and stabilization. You can keep your bones healthy with a few simple habits, like:

If you have ongoing or severe pain, leg deformity, or you can’t use or move your leg, especially after a fall or accident, seek medical attention.