The lower leg bone is composed of three parts: the FIBULA (6 letters), TIBIA (5 letters), and SHIN (4 letters). The FIBULA is the smaller of the two bones in the lower leg, located on the outer side of the leg. The TIBIA is the larger of the two bones, located on the inner side of the leg. The SHIN is the front part of the lower leg, located between the knee and ankle. Together, these three bones form the lower leg bone.