Why babies wobble, but don’t fall down

PURDUE (US) — Babies learning to stand may look unsteady, but are actually in more control than they appear, especially if they focus and hold on to an object like a toy.

“Babies learning to stand often sway and appear out of control, but in this study, once we handed them a toy their standing posture improved and they were more stable,” says Laura Claxton, assistant professor of health and kinesiology at Purdue University who studies motor development in children.

“Even though babies are top heavy and their neuromuscular systems are immature, this shows infants have more control when standing than many believe. Without the toy to hold, they go right back to being unstable.”

The findings, published in the Journal of Experimental Child Development, support previous research that says while swaying looks shaky, it’s just another way babies explore the environment.


Early instability is functional, Claxton says. Body sway provides sensory information that allows infants to learn how to appropriately control their body within their environments. However, too much body sway would make it impossible for the infants to focus on the toy, so infants reduce their amount of sway in order to better interact with the toy.

“These babies are shifting their postural strategies in a manner that helps them accomplish their immediate goals of either exploring the environment or engaging with a toy,” Claxton says. “They may look unsteady, but they are strategically adapting their behavior.”

For the study, 16 babies, averaging 11 months old, were independently standing but not yet walking. Their standing time, movement and stability when holding and not holding a toy was measured as they stood on a force plate. Video recordings also were used to compare movements captured by the force plate and the focus of the baby’s attention.

“We are interested in whether this is a learned behavior or innate,” Claxton says. It also could be that this posture control is learned when infants learn to independently sit or that their development systems adapt so quickly in just a few days of standing independently.

To answer these questions, long-term studies are needed to follow babies from sitting to standing and to walking to understand the continuum of motor development.

“Standing is not an easy task as babies learn to balance with a small base of support in relationship to their bodies, and it really says something about their development that the skill improves when they multi-task,” Claxton says. “This work doesn’t take place in a clinical setting, but research about infant and child motor development can ultimately help professionals monitor children’s growth and help develop therapies and assistance when there are problems.”

Claxton also is comparing these results to how babies alter posture and stability while fixating on pictures. She plans to extend this work to children who have difficulties with their balance, such as children with cerebral palsy and Down syndrome.

Researchers from Sacred Heart University contributed to the study.

Source: Purdue University