A newborn’s movement is controlled mainly by reflexes. The reflexes include asymmetrical tonic neck reflex (ATNR), Moro, rooting, sucking and swallowing reflex.
Due to the position in womb over 40 weeks, a newborn adopts a fetal posture. In lying, the arms and leg are held close to the body. On the tummy, the infant head is turned to one side, the buttocks are humped up and knees are flexed under the abdomen.
3 months old
The primitive reflexes are gradually disappearing while the baby gains more control over their neck and shoulder muscles. When lying on the back, the baby has enough neck strength to hold the head in midline. During pull to sit, there is little or no head lag. The baby is also beginning to understand his body, able move all 4 limbs symmetrically, bringing hands to midline for finger play. When lying on tummy, the baby can lift head and upper chest well off the bed, weight-bearing on forearm with buttocks flat on bed.
6 months old
Over the months, the baby has developed enough trunk and abdomen strength to roll from front toback and back to front. When lying on the back, the baby can raise his head to look at feet and bring the feet to mouth for exploration. At 6 months, the baby start sitting with support, balancing himself with his hands. When held standing, the baby weight bear well on both feet and bounces up and down actively.