It is important to recognize that motor development is a continuous process and that many of these skills are achieved within a range and not necessarily at a discrete age. The following offers some key developmental milestones in relation to age in months during the first year of life: Most children are able to lift and hold their heads up for brief periods of time while positioned on their tummies by two months of age. By four months of age, most children can keep their head and shoulders up while propped on elbows and forearms when on their tummies. Also, around this time, babies are able to hold a small toy when placed in their hand.