Have you ever asked yourself the question "Is my infant behaving normally?" That question may be better phrased as "what is typical for infants that are my baby's age?" As we stated in our introduction on our infant postural studies, the development of postural and locomotor milestones has been well documented. Below, we provide a table of some typical ages at which motor skills emerge. It is important to note the age range over which the emergence of these skills is considered 'typical'. Not every child accomplishes these tasks at the same time. Therefore, knowing the average age is not nearly as important as knowing the typical age range as well as the sequence of these skill developments.

Average Age (mo.)
Typical Range (mo.)
Behavior Description (according to Bayley Scales of Infant Development)
0.1
-
Lift head when held at shoulder
0.8
0.3-2.0
Arm thrusts in play
0.8
0.3-2.0
Leg thrusts in play
1.6
0.7-4.0
Head erect and steady
1.8
0.7-5.0
Turns from side to back
2.3
1.0-5.0
Sits with slight support
4.4
2.0-7.0
Turns from back to side
5.3
4.0-8.0
Sits alone momentarily
5.4
4.0-8.0
Reaches with one arm
6.4
4.0-10.0
Rolls from back to front
6.6
5.0-9.0
Sits alone steadily
7.4
6.0-10.0
Partial finger grasping
8.1
5.0-12.0
Pulls to stand
8.6
6.0-12.0
Stands up by furniture
8.8
6.0-12.0
Makes stepping movements
9.6
7.0-12.0
Walks with help
11.0
9.0-16.0
Stands alone
11.7
9.0-17.0
Walks alone