Wolff's Law states bones grow or remodel in response to what?

• A. Demands placed on them
• B. Nutrient intake
• C. Hormonal changes
• D. Blood flow

Answer: (A)

Wolff's Law describes how bone structure changes in response to the stresses and strains it experiences from use. When a bone carries greater mechanical load—such as from weight-bearing activity or the pull of muscles—the bone tissue adapts by forming more bone along the lines of stress, increasing its strength where it’s needed. If loading decreases, like during immobilization, bone can become weaker as it is resorbed. This idea centers on how the bone responds to mechanical demand, rather than merely on nutrients, hormones, or blood flow—those factors influence bone health overall, but the specific remodeling pattern is driven by the mechanical loads acting on the bone.