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Newborns are equipped with a number of reflexes (Table 3.1) which are involuntary movements in response to stimulation. Some of the more common reflexes, such as the sucking reflex and rooting reflex, are important to feeding. The grasping and stepping reflexes are eventually replaced by more voluntary behaviours. Within the first few months of life these reflexes disappear, while other reflexes, such as the eye-blink, swallowing, sneezing, gagging, and withdrawal reflex stay with us as they continue to serve important functions. Reflexes offer pediatricians insight into the maturation and health of the nervous system. Reflexes that persist longer than they should can impede normal development (Berne, 2006). In preterm infants and those with neurological impairments, some of these reflexes may be absent at birth. Once present, they may persist longer than in a neurologically healthy infant (El-Dib, Massaro, Glass & Aly, 2012).

Table 3.1: Some Common Infant Reflexes.
Reflex Description Image
Sucking Suck on anything that touches the lips. Black haired baby sucking on a nipple
Rooting Turning the head when the cheek is touched. Black and white photo of a hand touching the cheek of a baby having their mouth open
Grasp Fingers automatically grip anything that touches the palm of the hand. Black and white photo of a baby's hand holding an adult finger
Babinski The toes will fan out and curl when the sole of the foot is stroked from heel to toe. A baby's right foot spreading its toes
Moro A sudden noise or loss of support to the head and neck will cause infants to spread out their arms and legs, then quickly contract the limbs inward. Infant spreading out their arms and legs while laying down on their back
Tonic Neck When lying on the back with the head to one side, infants will extend the arm and leg on that side while flexing the limbs on the opposite side (looks like a fencer pose). Infants extending their arms while laying down on their back
Stepping Legs move in stepping-like motion when feet touch a smooth surface. Baby's legs moving in stepping-like motion while touching a soft surface

Motor Development

Motor development occurs in an orderly sequence as infants move from reflexive reactions (e.g., sucking and rooting) to more advanced motor functioning. As mentioned during the prenatal section, development occurs according to the Cephalocaudal (from head to tail) and Proximodistal (from the midline outward) principles. For instance, babies first learn to hold their heads up, then to sit with assistance, then to sit unassisted, followed later by crawling, pulling up, cruising, and then walking. As motor skills develop, there are certain developmental milestones that young children should achieve. For each milestone there is an average age, as well as a range of ages in which the milestone should be reached. An example of a developmental milestone is a baby holding up its head. Babies on average are able to hold up their head at 6 weeks old, and 90% of babies achieve this between 3 weeks and 4 months old. If a baby is not holding up his head by 4 months old, he is showing a delay. On average, most babies sit alone at 7 months old. Sitting involves both coordination and muscle strength, and 90% of babies achieve this milestone between 5 and 9 months old. If the child is displaying delays on several milestones, that is reason for concern, and the parent or caregiver should discuss this with the child’s pediatrician. Some developmental delays can be identified and addressed through early intervention.

 

Motor skills refer to our ability to move our bodies and manipulate objects. Fine motor skills focus on the muscles in our fingers, toes, and eyes, and enable coordination of small actions (e.g., grasping a toy, writing with a pencil, and using a spoon). Newborns cannot grasp objects voluntarily but do wave their arms toward objects of interest. At about 4 months of age, the infant is able to reach for an object, first with both arms and within a few weeks, with only one arm. At this age grasping an object involves the use of the fingers and palm, but no thumbs. This is known as the Palmer Grasp. The use of the thumb comes at about 9 months of age when the infant is able to grasp an object using the forefinger and thumb. Now the infant uses a Pincer Grasp, and this ability greatly enhances the ability to control and manipulate an object and infants take great delight in this newfound ability. They may spend hours picking up small objects from the floor and placing them in containers. By 9 months, an infant can also watch a moving object, reach for it as it approaches, and grab it.

Infant grabbing an adult's finger
Figure 3.8: Pincer Grasp.

Gross motor skills focus on large muscle groups that control our head, torso, arms and legs and involve larger movements (e.g., balancing, running, and jumping). These skills begin to develop first. Examples include moving to bring the chin up when lying on the stomach, moving the chest up, and rocking back and forth on hands and knees. But it also includes exploring an object with one’s feet as many babies do as early as 8 weeks of age if seated in a carrier or other device that frees the hips. This may be easier than reaching for an object with the hands, which requires much more practice (Berk, 2007). Sometimes an infant will try to move toward an object while crawling and surprisingly move backward because of the greater amount of strength in the arms than in the legs.

Milestones of Motor Development

We reflect on the matter, it becomes obvious that we have to be able to walk before we can run, and talk before we can sing. Infant motor development unfolds in a stepwise pattern. We understand the steps along the way as milestones. The following video provides a brief overview of some significant milestones in infant motor development.

Link Your Learning

As you watch the video below, consider the following guiding questions:

    1. What are the various milestones, and how do they unfold?
    2. Specifically, around when—and in what sequence—can we expect to infants to do the following?
        1. Develop head control
        2. Sit up independently
        3. Crawl
        4. Cruise around furniture
        5. Walk more or less independently

Milestones Checklists

Arnold Gesell was the first to develop a thorough calendar of developmental attainments linked to a child’s age. Published in 1925, the Gesell Developmental Schedules were the precursor to today’s updated developmental “milestones.”

In her article “What is a Developmental Milestone?,” Kendra Cherry provides an excellent introduction to the developmental milestones and how they are used to support child development from infancy to adolescence. There are many different versions of the developmental milestones, but generally the lists tend to look very similar. For instance, one popular way to assess milestones is the Ages & Stages questionnaires, which ask parents to assess whether their child has mastered milestones across all dimensions.

 

Link Your Learning

Take a look at the milestones included in the Ontario-based LookSee checklist, also called the Nipissing District Developmental Screening (NDDS) tool. Navigate to the website and look around. Be sure to review the FAQ page, in particular. Try to answer the following questions:

    • What is the LookSee checklist?
    • Who is the LookSee developmental checklist geared towards (ie. parents, childcare professionals, doctors, etc.)?
    • What developmental categories are measured by the LookSee checklist?

The LookSee developmental checklists are available free of charge to any Ontario residents. You can enter your e-mail address and retrieve the free version. After gaining access, review the developmental milestones checklists for infants, ranging from ages 1 & 2 months up to 18 months. Do you or someone you know have an infant? If so, try completing the age-appropriate checklist for the child.

 

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Lifespan Development: The Human Journey Copyright © 2024 by Humber College is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.

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