The first couple of years of a baby's life are the ones which are most crucial for the baby's development, both physical and mental. During this period, as the baby grows in age, one can observe several changes in the baby, the most notable being the efficiency of their voluntary physical movements. This is referred to as "motor development". Although these changes occur all through our lives, but the initial 18 years of a person's life see the most significant changes, more so in the period of infancy.
The term "infant" generally refers to a very young offspring, lying in the age bracket of 1 month to 24 months (2 years). As adults, we hardly notice the effort that we put in for maintaining our balance while standing upright or walking. These actions become so integral to our life that they can be termed as partially involuntary actions on our part. But for an infant, actions which seem of little effort to us are completely new. Maintaining their posture in different positions, having a control over their bowel movements are some of the actions which infants need to learn in order to ensure that these 'involuntary actions' (for them) do not restrict their physical movement.
Till the time an infant gathers some degree of control over his physical strength, his involuntary reflexes ensure his survival. These include sucking (necessary for feeding), rotting and the grasping reflex.
Physical Growth
The average weight with which a baby is born varies from region to region. In its first week, the infant may undergo some weight loss due to resorption and urination of the fluid that usually fills the lungs. But this is a temporary phenomenon. The weight gain starts after the first week and within 2 months, the infant not only reaches back to its the birth weight but also gains between 1 lb. 4 oz. and 1 lb. 12 oz. of weight.
In terms of height, the growth is about 2 inches during the first couple of months. Apart from the usual parameters of height and weight, one more important development in the first few months of an infant's life is the increase in the head circumference. There is an increase of an inch in the head circumference of an infant in its first two months. This is considered crucial as it reflects brain growth.
Another important aspect of physical changes that occur in an infant's initial months is the closing of the posterior fontanelle. This denotes the closing of the gap between the bones of the human skull, in which if there is a delay, it may be a case of congenital hypothyroidism.
Reflexes
As mentioned earlier, the involuntary reflexes of an infant makes sure that he survives in the initial months. Some of the important developments with regard to these reflexes are discussed below:
· Doll's eye reflex – As the name suggests, this refers to the reflex, whereby when you turn the head of a baby from side to side, its eyes will remain stationery, similar to that of a doll. But this reflex starts disappearing in the first couple of months, denoting brain growth.
· Crawling reflex – This reflex is observed only in the first month, during which if the baby is in a position where his stomach faced downwards, then it will draw its legs up under its belly, assume a fetal position (as if in a womb) and then start pushing its legs outwards, hence crawling.
Crawling reflex
· Walking reflex – Present at birth, by virtue of this reflex, when the infant is made to stand up and the sole of its feet touch a flat surface, it will attempt to walk by placing one foot in front of the other. This disappears in two months, only to return around 8-12 months as a voluntary activity.
Walking reflex
· Rooting reflex – Extremely strong in the initial months of an infant, this reflex helps in breastfeeding. Whenever the baby's cheek or mouth is stroked, the baby's head will turn in search of the object that touched it and it will open its mouth wide. This reflex weakens considerably after two months.
Rooting reflex
· Hand grasp reflex – During the first two months, whenever a finger is placed in the open palm of an infant, this reflex causes the baby to grasp it. Moreover, if the finger is sought to be removed, the grasp of the baby tightens around it. This disappears at around three months.
Grasping reflex
Motor skills
Motor skills in infants can be segregated into two types:
· Gross motor skills
· Fine motor skills
Gross motor skills refer to the ability of the infant to control large muscles of the body, for instance, the movement of arms and legs. Fine motor skills, on the other hand, are the ability to move the smaller muscles of the body. Motor skills develop in an infant in an order, with gross motor skills seen to be developing before fine motor skills.
During the first two months, the baby's hands are frequently observed in an open position. Also, it is observed that initially, the baby is unable to maintain the position of its head. For instance, when it is made to sit up, it may not be able to hold its head straight. But with the development of gross motor skills, the infant can finally do so. In fact, maintainance of head position is one of the most important gross motor skills as the position of the head also affects the area of vision of the baby. When the baby is on its tummy, it is able to lift its head by almost 45 degrees. With the infant gaining more ability to control the larger muscles, there are reductions in extreme flexions when the baby is on its stomach as it can move its hands and legs relatively better.
Baby lifting head
Fine motor skills development ensures that the baby's movements are much more co-ordinated. Earlier, the baby may just move its hands towards an object that it wants to pick, but if fine motor skills are developed then it may actually control the movement of the finger muscles too, ensuring that it actually picks up the object.
