The foot consists of 26 bones. (28 if you include the two sesamoid bones under your 1st metatarsal). The great toe ig generally longest in the most feet, however it is common for the 2nd toe to be longer than the great toe. (this is commonly referred to as 'the greek foot')
The main join of concern in biomechanics is the Subtalar Joint which is the joint between the Calcaneus (heel bone) and the Talus.
The proper function of these joint is crucial to a correct and 'pain-free' gait.