Here is what you need to know about the physical assessment for infant primitive reflexes.
Expected age for rooting reflex is birth to six months. The infant will turn the head to the side when the cheek of mouth is touched.
Expected age for palmar grasp is birth to four months. The infant will grasp the object when palm is touched.
Expected age for plantar grasp is birth to eight months. The infant’s toes will curl downward when the sole of foot is touched.
Expected age for moro reflex is birth to six months. The infant’s legs will flex when startled. The arms and hands will also extend.
TONIC NECK REFLEX
Expected age for asymmetric tonic neck reflex is birth to three to four months. The infant will go into fencer position. I also consider this to be a fighting position where the arm and leg will extend on the side when the head is turned to that side. The arm and leg will flex from the other side.