Final answer:
Fractures in school-age children are most often caused by activities that involve excess bending stress on the bone, such as sports that involve repetitive foot striking or hard falls onto an outstretched hand.
Step-by-step explanation:
Fractures in school-age children are most often a result of activities that involve excess bending stress on the bone. These activities can include sports that involve repetitive striking of the foot on the ground, such as running, tennis, basketball, or gymnastics. Additionally, hard falls onto an outstretched hand can also cause fractures in the upper limb bones.