Typical development
A typical infant tends to follow a known developmental progression that starts at birth with developmental psychology8. As the infant grows and his central nervous system9 matures, the gross motor skills develop (through Motor Neurons1) in a head to foot progression. First, at about two months of age, the infant will learn to hold his head up in attempt to look at the world around him. As he begins to notice light and sounds, the curious infant will look from side to side (cause and effect10), developing strength and coordination in the neck and upper back muscles. At three to four months an infant will often roll over for the first time while desperately trying to reach for a favorite toy that is just beyond reach (Diamant, 1989).
Around six months of age, when placed in a sitting position, the infant keeps himself balanced by propping himself up with both arms. Within a month or two, he is able to get into and out of the sitting position without any help, and use both hands to explore a toy. On the floor he can scoot across the room on his tummy, and later get up on his hands and knees to crawl. Generally by a year of age, the infant has figured out how to pull up to stand, cruise along the furniture, and maybe even attempt a few steps alone, until he is finally walking, climbing, and getting into everything.
Effects of disabilities
When an infant is developmentally delayed or neurologically2 impaired, these motor skills are often delayed, and do not develop easily. Gross motor skills occur in a typical sequence. However, these skills can only occur as the infant develops the balance, coordination and postural3 control needed to move his body about in space......
