For people with knee osteoarthritis, does high-intensity walking help or hurt? A group of researchers who examined this question presented their findings at the Annual Meeting of the American College of Rheumatology (October 2018). With osteoarthritis, the cushioning cartilage that covers the ends of bones in joints wears down, which can cause pain and stiffness. Exercise, including walking, is recommended. Past research has been mixed on whether walking too briskly can cause further injury. The current study included over 1,800 people with knee osteoarthritis. They wore accelerometers (which measure step cadence to determine walking intensity) four or more days a week for five years. Participants who replaced five minutes per day of non-walking time with five minutes of moderate-to-vigorous intensity walking reduced their chances of having total knee replacement by 16 percent. Light intensity walking had no such effect.