Physical conditions or diseases that can cause knee pain: 1  osteoarthritis: pain, inflammation, and joint destruction caused by degeneration and deterioration of the joint. 2  tendinitis: pain in the front of the knee that is made worse when climbing, taking stairs, or walking up an incline.
Ages Of US Presidents. John F. Kennedy is the youngest-ever elected president, aged 43. However, Theodore Roosevelt is the youngest person to ever become president. He was 42 when he succeeded to the presidency, following the assassination of McKinley. Ronald Reagan is the oldest person ever to be elected president. He was 69.
Browse this list to see who were the youngest-and oldest-Presidents in history. 1  Theodore Roosevelt (42 years, 10 months, 18 days). 2  John F. Kennedy (43 years, 7 months, 22 days). 3  Bill Clinton (46 years, 5 months, 1 day). 4  Ulysses S. Grant (46 years, 10 months, 5 days). 5  Barack Obama (47 years, 5 months, 16 days).