Final answer:
Greenstick fractures occur in infants and children because their bones bend more easily than an adult's.
Step-by-step explanation:
Greenstick fractures occur in infants and children because their bones bend more easily than an adult's. These types of fractures happen when a bone bends and cracks, instead of breaking completely. Because children's bones are still growing and developing, they are more flexible and have more elasticity, which makes them more prone to greenstick fractures.