Which bone is the outer and smaller bone of the lower leg?

The fibula is the outer and smaller bone of the lower leg. It runs parallel to the tibia, which is the larger bone located on the inner side of the leg. The primary function of the fibula is to provide stability to the ankle and support for muscles of the lower leg. While it contributes to the structure of the leg, it does not bear significant weight compared to the tibia. This anatomical arrangement allows for better balance and mobility, with the fibula assisting in lateral stability. The other bones listed serve different roles within the skeletal system; the tibia is the primary weight-bearing bone, the femur is the thigh bone, and the sacrum is part of the pelvis.