Definition: The word 'appendicularian' refers to a type of foot bone, specifically an femur (knee) that joins two metatarsal bones in the big toe. Definition: It's a term used by medical practitioners to describe the foot joint at which the inner side of the ball of the foot fits against the inside of the big toe. This joint is known as an 'appendicular' because it comes from the word 'appendix,' meaning a large, hollow part in a body that holds blood and tissues. In terms of anatomy, this joint is unique among bones in the leg - not just one bone but two: a femur (knee) and a tibia (fistbone). The femur supports the weight of the foot while the tibia helps with motion and flexibility. This structure is very important for supporting the body's balance and stability, as well as providing support when walking or running.