Physical Development in Infancy

Study Notes

Infants experience rapid physical growth, particularly in the first three months.
Weight and height increase significantly during this period, alongside energy and nutrient intake, with rapid fat accumulation.
Height increases by approximately 25cm in the first year after birth.
Weight typically increases by around 7kg from about 3kg, reaching approximately 10kg by the end of the first year.

Infant bodies exhibit rapid growth, especially within the first three months.
Energy and nutrient intake increase dramatically, accompanied by rapid fat accumulation.

Newborn infants have a standard weight range of roughly 3kg, and a body length of about 50cm.
Neonatal vision and hearing are present but relatively weak, with gradual adaptation to the environment.
Weight and length increase rapidly in the first period after birth, typically around 30% or more.

Babies develop the ability to look up, a sign of neck and back muscle development.
Improvements in vision and hand coordination lead to babies paying attention to and attempting to touch objects.
This marks the start of hand muscle and coordination development.
Facial muscles start to develop, leading to an increasing ability to express emotions, especially smiling.

Infants learn to turn over from supine to prone, and vice versa, demonstrating balanced, coordinated development.
Vision improves, enabling clearer sight and enhanced perception of color and shape.
Babbling and unconscious sounds become apparent, demonstrating early language development.

Infants can now maintain a seated position, although support might be required.
Emotional expression becomes more pronounced, showing a greater ability to express emotions.
Infants start to learn to grasp objects by hand, enhancing hand-eye coordination.

Babies begin crawling, enabling exploration of the surrounding environment.
Hand movements become more flexible, with the development of the use of thumb and forefinger.
Emotions and needs are expressed more clearly through vocalizations and expressions.

Babies develop the ability to stand.
Finger flexibility is improved, which aids in intricate grasping and placing actions.
Babies start to make more conscious sounds (like calls) which represent the early stages of language development.

Larger head size. As brain tissue develops and perfects, skull size increases.
The fontanelles (soft spots) are still closed between 3 and 6 months, making the skull and head structure important for evaluating health and development.
The spine is initially soft, especially in the cervical and lumbosacral regions. This is a normal characteristic of infant development.
The spine gradually gets rigid with development and movement.
Proportion of limbs and trunk is symmetrical, and skeletal muscles develop.
Posture becomes stable. Stable posture is essential for promoting physical coordination.