National Board of Chiropractic Examiners (NBCE) Practice Test

Which of the following is an example of Wolff's Law?

1. Scoliosis during adolescence causing wedge-shaped vertebral bodies

2. Fracture healing leading to increased bone density

3. Osteoporosis following prolonged bed rest

4. Bone remodeling due to mechanical stress

The correct answer is: Scoliosis during adolescence causing wedge-shaped vertebral bodies

Wolff's Law states that bone adapts to the loads under which it is placed; that is, bone in a healthy person or animal will remodel itself over time to become stronger in response to those loads. The correct choice illustrates this principle as it highlights how scoliosis during adolescence can lead to the development of wedge-shaped vertebral bodies. The abnormal curvature of the spine creates uneven forces on the vertebral bodies, which, over time, will adapt to these mechanical stresses, resulting in changes to their shape. This demonstrates Wolff's Law in action, as the bone structure alters in response to the mechanical demands placed on it. Other options involve conditions that are influenced by bone density or health but do not specifically exemplify the adaptive remodeling of bone according to Wolff's Law. Fracture healing focuses on recovery and restoration but does not specifically illustrate how bone adapts to loads. Osteoporosis due to inactivity refers to the loss of bone density, which does not showcase the strengthening response of bone to stress. Finally, while bone remodeling due to mechanical stress relates to Wolff's Law, the specific example of scoliosis provides a more direct and illustrative case of the law’s principles in action.