Physical Therapy Assistant Practice Exam

Which reflex is stimulated by head positioning in flexion or extension?

1. Tonic labyrinthine reflex

2. Crossed extension reflex

3. Symmetrical tonic neck reflex

4. D1 extension pattern

The correct answer is: Symmetrical tonic neck reflex

The symmetrical tonic neck reflex (STNR) is stimulated by head positioning in flexion or extension. When the head is in flexion, the arms flex while the legs extend, promoting a coordinated movement pattern that facilitates crawling and transitional movements in infants. Conversely, when the head is in extension, the arms extend and the legs flex, allowing for stabilization of posture and balance as the infant prepares to move. Understanding the STNR is important in physical therapy, especially when working with children or in rehabilitation scenarios where posture and movement coordination are crucial. This reflex is typically present in infants from around 6 to 12 months old and plays a significant role in the development of gross motor skills. Consequently, the STNR can be a focused area during therapeutic interventions to improve motor control and function. Other choices refer to different reflexes that are not directly related to head positioning in the same way. The tonic labyrinthine reflex is more responsive to changes in head position relative to gravity, while the crossed extension reflex involves different body parts reacting to stimuli affecting one leg. The D1 extension pattern pertains to specific patterns of movement rather than a reflex that responds to head positioning. Appreciation of the STNR allows for better assessment and intervention strategies tailored to patients needing support in