And why it is important to encourage hand function in infants at risk for developmental delay
Author: Pam Versfeld Physical Therapist
Moving to learn. Learning to move.
Infants are born with a brain that is wired for rapid learning through experience and this learning is in large measure driven by the quality and quantity of their engagement with their social and physical environment. Movement underpins all early experience: movement of the eyes and head allows the infant to look around and turn towards interesting sounds and sights, movement is needed for feeding and communication (crying, smiling, babbling), social interaction depends of facial expressions, and movements of the hands and feet allows the infant to start exploring the environment through touch and later grasping and manipulation.
Movement experience sculpts the brain by influencing the connections between the different areas of the movement, social, emotional, language and cognitive (thinking and attention) areas of the brain. Each opportunity to explore new ways to use the hands or to repeat already learned actions strengthens these connections and create representations of events that can readily be accessed at a later stage to guide behavior.
Most healthy infants are very motivated to move and use their hands to engage with, and explore, their world - they are alert, curious and willing to take on new challenges. Some infants who have a very cautious nature, may be less active and easily become distressed so that they spend less time actively engaging and exploring.
Infants born preterm, especially those who have had to cope with many medical issues are often less active and their exploration may be hampered by atypical brain development, as well as muscle weakness and low muscle tone which affects their ability to steady the head and trunk and move the limbs.
How very young infants use their hands
From birth infants are attuned to the sights and sounds in their environment. An awake and alert newborn will gaze with great interest at a mom or dad's face, and will turn the eyes and head to look towards interesting sounds and moving objects that come into view.
Very young infants are particularly interested in hands - and will preferentially look at their own hands and those of their caregivers.
At the same time the ongoing spontaneous movements of the arms that occur when the infant is awake and alert, bring the hands into contact with their own bodies and the surrounding surfaces.
Initially this contact is accidental, but very soon infants starts to use the fingers to explore the surfaces they touch. This early exploration is one way that very young infants use their hands to actively connect with the environment and build connections between the the motor and sensory areas of the brain.
Infantd also actively practice different movements of the fingers - they open and close the fingers in a grasping action, but also practice impendent movements of the fingers and will point with the forefinger, and bend and straighten individual fingers.
Within weeks alert infants start to move their hands towards towards interesting objects that catch their visual attention and are within reaching distance.
This remarkable feat requires some complex brain work - the infant needs to transform the visual information about the position of the object in space (relative to the body) into a set of commands that will move the hands in the right direction. With practice infants learn to reach with greater accuracy.
At three months typically developing infants have learned to hold the head and trunk steady and this allows them to reach for, grasp and manipulate objects with greater precision. Bringing the hands together in the midline also allows the infant watch what the hands are doing.
Infants start to bring toys to their mouths which allows them to integrate visual information (what it looks like), information from the fingers (what it feels like) and information from the lips and mouth (what it feels and tastes like).
At this age the infant still does not hold an object in the hand for very long, but will reach for, grasp and manipulate interesting toys that are suspended within easy reach. Because the object stays in place the infant is able to spend time visually inspecting the toy, grasping and letting go, and feeling it with their fingers.
Such extended play experiences are important for learning about the properties of objects: this is what it looks like, this is how it feels when I touch, stroke, pinch it, this is what happens when I move it with my fingers. This experience also improves the control of the arm and hand: movements become smoother and more accurate with repeated practice.
Fast forward to a time when the infant can sit independently. Sitting erect means that the infant can see and reach for toys that interest her and use both hands to grasp, move and manipulate them in different and interesting ways.
Sitting infants also start to use their heads and hands for communication. One of the earliest non-verbal communication gestures is shaking the head to so no. Infants will often open and close their hands to indicate that they want something. They start to use pointing to draw attention to events and objects.They copy the gestures used by their caregivers - palms turned up to say: Where has it gone? Bringing the hands together to indicate more or again. Clapping or lifting the hands above the head to communicate pleasure and a sense of achievement.
Some infants need extra encouragement to promote exploratory manual behavior
Most typically developing infants living in a safe and supportive family environment are highly motivated to move and will use all the available opportunities they encounter during the day to use their hands to explore their surroundings and objects within reach.
Infants who were born preterm (preemies) and those with developmental conditions that affect movement often need extra help to encourage active exploration, early reaching and manipulation, including
► Preterm infants (preemies), especially those who are risk (Lobo et al 2015)
► Down syndrome infants
► Joint hypermobility, low muscle tone and muscle weakness in preemies and infants with Down syndrome and other developmental disorders affecting movement may also have an impact on active exploration.
► Infants with a high risk for autism
How parents can encourage exploration, early reaching and manipulation
For infants who are developing typically and who are motivated to move, there are many books and web resources that provide parents with information about activities that are suitable for infants at different ages. However, parents and caregivers of for infants with developmental delay, who were born preterm, Down syndrome, have atypical brain development and those who are not motivated to move, need more information and guidance than can be found in the baby books and websites.
Parents need to know how to motivate the infant to move and explore, and how to adapt activities to allow the infant to succeed is very important. It is not just a matter of doing more - but a case of doing differently and having the knowledge to adapt and change the tasks and environment to motivate the infant to engage and explore.
Some simple ways to provide the right environment for promoting hand use and brain growth
Very young infants do a lot of learning when they are awake and alert and lying on their backs on a flat, firm surface. The spontaneous movements of the limbs helps to strengthen not only the arm and leg muscles, but also the neck and trunk muscles which are important for postural stability.
Infants can be encouraged to kick more actively by letting them lie on a surface that makes a noise or attaching bells to a hand or a foot.
Providing the infant with some postural support for the head and trunk will also enhance spontaneous movements of the limbs and active exploration with the hands
Playing finger games with infants will often promote infant attention and individual finger movements
A play mat that allows one to suspend toys to encourage the infant to look at, each for and manipulate.
Putting toys within easy reach for infants in a reclining seat creates another opportunity for sustained visual, reaching and manipulation behaviors.
For therapists: The Development of Hand Function 0-18 months
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Bornstein, M. H., Hahn, C.-S., & Suwalsky, J. T. D. (2013). Physically Developed and Exploratory Young Infants Contribute to Their Own Long-Term Academic Achievement. Psychological Science, 24(10), 1906–1917. http://doi.org/10.1177/0956797613479974
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The development of bimanual actions reflects perceptual, motor and cognitive processes, as well as the functional connectivity between brain hemispheres. We investigated the development of uni- and bimanual actions in typically-developing (TD) infants and infants with Down syndrome (DS) while they reached for objects with varying sizes. Eight TD infants and seven infants with DS (ages 4 to 8 months) were tested at several stages of reaching experience. Movement strategies at movement initiation, object touching and grasping were recorded. With reaching experience, typical infants increased ability to anticipate reaching strategies, and independent use of the hands according to task demands. Strategies used by infants with DS were mostly compensatory rather than anticipatory, and showed a weaker tendency for interlimb coupling at early ages. These differences may underlie functional limitations, and should be subject to early intervention.
Yu, C., & Smith, L. B. (2017). Multiple Sensory-Motor Pathways Lead to Coordinated Visual Attention. Cognitive Science, 41(Suppl 1), 5–31. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5387763/
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Infants born preterm explored objects less in the first 6 months, exhibited less visual-haptic multimodal exploration, displayed reduced variability of exploratory behavior in a manner that reflected severity of risk, and were less able to match their behaviors to the properties of objects in a manner that reflected severity of risk. Infants born preterm with significant brain injury also had impaired bimanual abilities.
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