Rosh Pediatrics Practice Exam

Which developmental reflex is expected to last beyond 1 year of age in a normally developing child?

1. Extension and abduction of the arms with palms open

2. Flexion of the toes downward to "grasp" an examiner's finger

3. Reflexive extension of the upper extremities toward the ground

4. Twitching of the hips toward the side of the stimulus

The correct answer is: Reflexive extension of the upper extremities toward the ground

The reflex expected to last beyond 1 year of age in a normally developing child is reflexive extension of the upper extremities toward the ground. This reflex is also known as the parachute reflex. It typically emerges around 6 to 9 months of age and remains present throughout life. This reflex represents a critical aspect of an infant's protective responses. When an infant is pushed forward, they reflexively extend their arms outward to protect themselves from falling. This ability to reach out can be linked to the developing motor skills and balance in toddlers and beyond. In contrast, the other reflexes mentioned are temporary and generally diminish as the child grows. For example, the extension and abduction of the arms with palms open is often associated with the moro reflex, which typically disappears by around 4 to 6 months. The downward "grasp" flexion of the toes is related to the plantar grasp reflex, vanishing around the same time. Additionally, the twitching of the hips toward the side of the stimulus is indicative of a primitive reflex that generally fades out by the end of the first year, rather than persisting. Thus, reflexive extension of the upper extremities is the only reflex among the options that is expected to last beyond