Hi Robert, great article on arthritis! As a highly active 25-year-old who experienced arthritis a few years back, I would add one other explanation for why rates are skyrocketing: gut-related inflammation. It wasn't until I fixed my gut issues and addressed food sensitivities that my inflammation went down and then my arthritis disappeared. While lack of movement, or improper movement, is one issue, systemic inflammation related to food or persistent gut issues is also a growing epidemic (e.g. look at the rise in gluten intolerance or people opting for plant milks). Just wanted to add in my 2 cents on the arthritis rise :) overall, great article