- Calcaneus, cuboid + talus ossified at birth
- At 3 years secondary ossification centres for navicular, MTs + phalanges appear
- Secondary ossification centre for calcaneus is last to ossify at 10 years
- Accessory ossicles → os fibulare (lateral border cuboid) & os tibiale (medial aspect of navicular) present in 10% of the population
- Os trigonum (posterior lip talus) present in 13% of the population
