Final answer:
The fibula is the slender bone located on the lateral side of the leg, paralleling the weight-bearing tibia on the medial side. It is responsible for muscle attachment and forms the lateral part of the ankle joint but does not bear weight itself.
Step-by-step explanation:
The fibula is a slender bone located on the lateral side of the leg. It runs parallel to the larger tibia which is situated on the medial side and is responsible for bearing the weight of the body. Unlike the tibia, the fibula does not bear weight, but it provides sites for muscle attachment and plays a crucial role in stabilizing the ankle by forming the lateral malleolus, the bony protrusion that can be felt on the outer aspect of the ankle. This bone is largely surrounded by muscles, and only its proximal and distal ends can be easily palpated.
The proximal end of the fibula, known as the head of the fibula, articulates with the tibia at the lateral tibial condyle to form the proximal tibiofibular joint. The interosseous border runs along the medial side of the fibula and serves as the attachment for the interosseous membrane, which is a connective tissue sheet uniting the fibula and tibia. At the distal end, the fibula articulates with the tibia at the fibular notch and with the talus bone of the foot, contributing to the ankle joint formation.