Physical Development of an Infant
Growth is rapid during the first two years of a child’s life. Parents should be aware of physical changes during this stage. Diet, sleep, schedules, activities and safety policies need to be adjusted as the children grow. For example, infants can be kept in cribs or playpens most of the time since they don’t have enough muscle strength to move around much. By ten to twelve months though, children need space for crawling and walking since their muscles have developed considerably. 
Size
The baby’s average weight at birth is about 7 pounds. After four months, the infant will have doubled in weight. At one year old, the child normally weights about three times his birth weight. By the time he reaches two years old, the typical child weights almost four times his birth weight. The infant’s length also changes rapidly. At birth, the average infant measures 20 inches. By the end of a year, the infant has usually grown 10 inches more. In two years, most children measure from 32 to 56 inches in height. There are also growth differences between boys and girls at two years of age. Most boys are slightly heavier and taller than girls at this stage.
Reflexes
A reflex is an automatic body response to a stimulus. The baby’s physical abilities are limited to reflexes. These are the rooting and suckling reflexes. The rooting reflex causes the baby to turn his head towards anything that brushes their faces. This reflex helps the baby to find a food source, such as the mom’s breast. Once an object is near his lips, they immediately start to suck. Doctors check the reflexes of children to assess their brain and nerve development. They test the infant for the MORO, BABINSKI, GRASPING, SWIMMING AND STEPPING REFLEXES. If these reflexes are not present in an infant, this may be a sign of brain or nerve damage. Moro reflex occurs when an infant is startled by a noise or sudden movement. The infant flings his arms outside and then quickly draws them into his chest. This reflex usually lasts up to three months after birth. Babinski reflex occurs when you stroke the sole of the infant’s foot on the outside from the heel to the toe. When you do this, the baby will fan his toes upward. This reflex usually lasts for the first year after birth. Grasping reflex can be observed by touching the infant’s palms. The baby’s hands will grip your fingers tightly. This can also be seen if an object is placed across his palm. This reflex disappears after three to four months after birth. Swimming reflex can be observed if you hold an infant horizontally, face down, on a surface. The baby will stretch out his arms and legs in a swimming motion. This reflex lasts for six months after birth. Stepping reflex occurs when you hold the infant so that his feet are flat on a surface. The baby will move his legs in a walking motion. This reflex lasts for six months after birth.
Motor Sequence
Motor sequence refers to the order of movements performed by an infant. Each new movement builds upon the previous abilities. Motor sequence depends on the development of the brain and nerves. This is why movements tend to develop first in areas closest to the brain and spinal cord.
First Three Months
In the first three months, head and trunk control develops. The infant can lift his head from a surface, and watch a moving object by moving his head from side to side.
Four to Five Months
By four or five months of age, the baby can roll over. At first, the baby can turn from the stomach to the back. Soon after, the baby can roll from the back to the stomach.
Six Months Onwards
By six months, the baby is able to sit. After this, crawling follows, pushing with legs and reaching with arms. This skill occurs soon after the baby learns to roll on his stomach. Gradually, the arms and legs strengthen. Soon, the baby is able to creep. Creeping is a movement of the baby using the hands and knees to support his body weight. Then he can move his arms and legs to go forward. Soon, the baby can stand with the help of an adult. Then he can stand while supporting himself from a furniture. With better leg strength and coordination, the baby can walk when led by an adult. Next, the baby can stand without any the support and finally walk without any support and finally walk without any help from an adult. The skills discussed here are considered normal because most infants at that age can do the said skills. For this reason, you should not worry if your baby cannot do the expected skill for his age. Many children may develop certain traits at an earlier or later age. However, you need to seek help if your baby is way behind the norm.
