Longest bone, whose head fits into acetabulum of hip girdle. The distal or lower end bears intercondylar groove and patellar groove.
Small, flat, triangular sesamoid bone (small, like a sesame seed), formed by the ossification in the tendon of quadriceps femoris muscle. It is articulated to femur and lies in front of knee joint.
Tibia is large, short and straight. It lies more medially and in front. The two condyles form the articular surface for tibia.
Proximal end of tibia is concave for articulation with femur and knee cap. The distal end of tibia, which articulates with the talus bone of ankle, has a single strong medial process called medial malleolus which form the inner prominence of ankle.
It is shorter, thinner and slender. It lies more internally and deeply. Its upper ends articulate with upper end of tibia but do not reach the knee joint.
Its lower end articulates with the end of tibia as well as the talus by means of lateral malleolus.
Tibia and Fibula are free proximally but fused distally, hence name tibio-fibula.
They have seven tarsals arranged in three rows – middle with single navicular, proximal row has calcaneum forming heel and talus that is articulated with both tibia and fibula.
6. Metatarsals and phalanges are bones of sole and toes. Digital formulas of phalanges are 2, 3, 3, 3, and 3.