There is also a soft tissue in between the two bones, called the interosseous membrane, which runs the length of the two bones and binds the two bones together to keep them stable. The tibia and fibula are connected by ligaments underneath the knee and at the ankle. It forms the base of the knee called the tibial plateau and extends down to form the inside of the ankle joint. Next to the fibula bone is the tibia, which is thicker. The fibula is a slender and long bone located on the outside of the lower leg, from outside and underneath the knee and extends down to form the outside of the ankle joint. Seek emergency medical attention if you think you might have a fracture, particularly if the fracture breaks skin and bone is visible. A fibula fracture happens when more pressure is put on the bone than it can handle. The fibula only carries 17 percent of the body’s weight.
However, this bone has no significant role in supporting the body weight. Instead, the fibula helps stabilize and support your leg, body, ankle, and leg muscles. The fibula is a long and thin bone runs parallel to the tibia, a larger bone that also forms the shin, and attaches the ankle and knee joint. The bone outside the leg is the fibula, which is the smaller one. Most of the weight of the body is carried by the tibia (the larger bone of the lower leg).