Physical growth occurs in an orderly sequence, meaning it is cephalo-caudal (occurs from the head to the feet) and from the center of the body outward. In other words, an infant is not able to sit up until they have head control and won’t walk until they have mastered sitting without support. Likewise, they are not able to master fine motor skills like a pincer grasp until they are able to move the arm and hand in a sweeping movement.

While milestones have been developed for physical growth there is individual variability, meaning inherited genetic characteristics. For example, growth deviations could be constitutional growth delays. This is the reason sequential measurements are important, one height and weight plot on the growth chart is not very helpful, it is necessary to look at the trend over a period of time. Individual variability involves such factors as:

• Congenital syndromes
• Congenital malformations
• Ethnicity
• Cultural practices