Volume 12, Number 2, 2003
In the Department of Physical Therapy's Motor Behavior Lab, research on infants' motor skills is resulting in findings that could change long-held notions about human development and reinvent the way infants are tested and treated for developmental problems.
James C. (Cole) Galloway, assistant professor of physical therapy, says his studies of how babies kick their legs and flap their arms indicate that such movements don't necessarily follow the fixed developmental pattern known as "cephalocaudal progression."
Medical professionals, such as physical therapists, and researchers alike use that term to describe the motor development of infants. It signifies a specific pattern of movement that follows a rigid sequence, beginning with the ability to control the head and neck, then the arms and continuing down to the hips and legs. Galloway and a growing number of other researchers have found that the development of even the earliest motor skills is more complex than traditionally believed.
"We are attacking longstanding assumptions about how humans learn to move," Galloway says, noting that the assumption is often that our motor behaviors are predestined--that is, hands are predestined to reach and feet to walk.
In his earlier work, Galloway says he "saw something different about the legs and arms." He noticed that newborns move their legs in a stereotypical alternating pattern, whereas they move their arms in a wide variety of patterns.
Every parent knows that infants can kick well before they gain control of their arms, but researchers had always believed that these kicking motions were purely involuntary--or at least not precisely controlled. Galloway's research has provided evidence to the contrary.
Placing a toy in front of the babies' legs, Galloway watched as they reached out and contacted it with their feet. Moreover, these infants contacted the toys with their feet up to a month before they could do the same with their hands. Infants' aiming their feet to contact an object at such an early age is a striking deviation from the cephalocaudal rule. If it turns out that the majority of infants can reach with their legs, it would show that leg movements are neither random nor involuntary and that they can be used to determine whether infants are having developmental problems.
The extra month may not seem like a great deal of time, but when dealing with infants who are just 2-3 months old and at risk for development problems, a month can make a world of difference, Galloway says. "Early assessment and treatment is the key," he adds. "Therapists can begin treatment early on, instead of waiting four or five months for arm reaching to begin."
Galloway speculates that it is easier for infants to gain control of their legs before their arms because the arms have a wide range of movement, while the legs have much more restricted movements. Infants can repeat successful movements with their legs much more easily than repeating a movement with their arms.
Galloway says his research also applies to infants who are not at risk for developmental problems. "Exploration and brain development are closely related for every child," he says. "Babies have to learn about the world through interacting, and reaching is the first step toward independent exploration of their immediate world."
If infants are indeed reaching to interact with the outside world much earlier than previously believed, then children can begin learning and developing at an earlier age, Galloway says. "Development, of course, builds on the past," he says. "Therefore, a small increase in the ability to explore objects early on has the potential to have enormous impact on a child's later level of function."
Galloway also recently published work showing that healthy infants provided with increased arm movement, or flapping, were able to reach at an earlier age than is typical. Most infants do not gain enough arm control to reach until they are 4 or 5 months old, so Galloway uses a technique called "the mobile paradigm" to increase the amount of flapping. He straps soft bands around the babies' wrists and connects the bands to an overhead mobile. When the babies begin flapping their arms, they see the mobile move and begin to realize that they can use their arms to affect the outside world.
Decades of research have used the mobile paradigm to assess infant memory, but this is the first time that researchers have used the paradigm to train young infants. Galloway now is extending this work to see if babies born at risk can benefit from this special training and whether the training can influence the onset of successful feet reaching.
Galloway has received a grant from the National Institutes of Health to conduct a study determining when the average child begins feet reaching and to explore the transition between spontaneous movement and controlled movement. He will be studying infants 4 weeks old and monitoring them until they are 5 or 6 months old. He says he hopes to determine whether the extra reaching experience at earlier ages triggers faster development.
The initial project focuses on healthy infants. Follow-up studies with graduate students Jill Heathcock, Anjana Bhat and Michele Lobo will focus on infants born at risk for such coordination disorders as cerebral palsy. The University's Early Learning Center, which is set to open next year and will offer child care, clinical services and research as well as educational opportunities for UD students, will play an important role in his research project, Galloway says.
"Many labs, including ours, are very excited about the possibilities for conducting early intervention research in such a state-of-the-art facility," he says.
The results could give babies in this country a "leg up," but they also could be immediately useful in developing countries because the techniques are nearly cost-free, Galloway says. His research also will study the differences that culture and socioeconomic factors play in determining the rate of a child's development.
"This is important information, because reaching is not just reaching," Galloway says. "It's the gateway to interacting with the outside world."
--Dean Geddes, AS '05