Children, from infancy through adolescence, grow and change significantly as they reach different stages. The physical development of an infant begins with total helplessness and uncoordinated movements. As that same infant grows into a young teen, he has probably grown as big as his father or other relatives.
Infancy
At one month, your baby's movements are very uncoordinated. Her movements are jerky. When she is startled, she'll react with strong, physical reflexive movements--her arms and legs fly out in what's called the Moro reflex.
By two months, she should be able to raise her head and chest when she's on her stomach, open and shut her hands, push down on her legs when her feet are placed on a solid surface and swipe at dangling objects with her hands, according to the University of Michigan Health System.
At six months, she should be able to hold her head steady when sitting with your support, play with her toes, transfer toys from one hand to the other one, roll over, and help hold her bottle when she's being fed.
Preschool
By the time your preschooler is three years old, he should be able to manipulate a spoon with food on it, although he will spill some food as he's feeding himself. He should be able to throw a ball over his head, although his aim won't be accurate.
At four years old, he should be able to feed himself with little spillage, hold a pencil, draw a face, try to print his name, unbutton some buttons, cut paper with blunt scissors, build a seven to nine block tower and pour water from a small pitcher.
When he's between four and five years of age, he should be able to stand on one foot for at least 10 seconds, skip, somersault and hop. He should be able to copy geometric shapes, print some letters and draw a person with a body, says the University of Michigan Health System. He should now be able to dress and undress with no help and take care of his own bathroom needs.
School Children
Your child's growth begins to slow and she enters what is called the "latent" stage, where she seems to stop growing. Her growth simply "goes underground." Her muscle control is not consistent and she enters a period where her movement becomes uncoordinated. During this stage of her life--six to about 12 years--she becomes clumsy.
When she is about to enter her teen years, she may experience a growth spurt. As she gets closer to the end of middle childhood, her movements become more coordinated. Her small muscles begin developing rapidly, making activities like playing a musical instrument or drawing something she might enjoy.
Adolescence
As your child becomes a young teen, his rate of growth rivals that of his infant years. Your son begins making marked gains in weight and height. In one year, he can grow an average of 4.1 inches. When he gains weight, this gain comes primarily from increased muscle development.
He begins to develop secondary sex characteristics such as voice change, growth of underarm and leg hair and penis growth. He also experiences facial hair growth as a young teen. Expect to see signs of acne. He'll also experience an increase in the activity of his sweat glands, leading to noticeable body odor.
