Proximodistal development describes the general trend for the development of motor abilities to occur from the center outwards.
First, the middle develops and then the movement spreads outward. Infants learn to move their torsos first, then their arms and legs.
Finger manipulation and other finely tuned movements will develop once motor skills for their limbs are developed. Motor development proceeds from the center of an organism to the periphery via proximodistal development.
Early motor skills are learned by parts of the body that are closest to the trunk before parts farther away in proximodistal development. In other words, gross motor skills like waving an arm develop before fine motor skills like writing legibly.