It has been proven that there is a reduction in flexibility of about ___ per decade from ages 20-49 years of age

• A. 5%
• B. 15%
• C. 20%
• D. 10%

Answer: (D)

Flexibility decreases with age as connective tissues stiffen and muscles lose some elasticity; collagen cross-links increase and hydration of tissues changes, contributing to reduced range of motion. In healthy adults from the 20s through the 40s and into the 50s, the typical decline in measured flexibility is about 10% per decade. So stating a ten percent reduction per decade from ages 20–49 aligns with what’s commonly observed. Smaller declines (like 5%) would understate it, and much larger declines (15% or 20%) would overstate the rate for that age span, making ten percent per decade the best fit.