Jitters or trembling of the arms and legs during crying is normal in newborns. It should stop by 1 to 2 months of age.

When do babies stop flailing arms?

You probably won't have a stopwatch out to measure this at home, so you might pay attention to when and why your child flaps their arms as well as other symptoms your child may experience. Arm flapping can be part of gross motor development. Repetitive behaviors tend to go away when a child is around 12 months old .

Why do babies jerk their arms?

Immature Nervous System

In newborns, the pathways that carry the signals from the brain to the parts of the body aren't yet fully developed, causing jerky and twitchy movements. As the baby's nervous system matures, these movements will become more fluid.