What are the risks & benefits of walking more than a few blocks, with so-called bone-on-bone arthritis of one knee? Does it necessarily damage the bones? Would it make future knee replacement impossible? Wouldn t it most likely *increase* bone density? (I have osteopenia, with one out of four measurements tending to be rated as normal ). Is it possible that bone-on-bone walking would smooth out the rough edges of the bones and actually make walking more comfortable, as a result? I am a 79 year old female and would be willing and able to walk at least 1/2 mile each way, if these fears would not stop me. The most typical level of my pain on relatively level city streets is rarely above 1 or 2, and almost never above 3. My knee arthritis started almost 40 years ago as a result of an injury. It has progressed very slightly, over the years, but the most significant consequence is that I go up and down stairs with difficulty, and I am afraid to walk far. I do think that fear of hurting myself by doing too much stops me more than weakness does, because once in a while, when I am highly motivated, I can go up and down stairs with complete comfort. When well rested, I can walk comfortably, for a while, too, and I may be aware enough to use the larger muscles of the legs, rather than sticking to my bad old habits of avoiding them. At my age, is it possible that I could become strong enough to drop the fears and become capable of walking comfortably most of the time? I exercise daily on a rebounder (mini-trampoline) for 10-15 minutes, getting up to a heartrate of about 110. I am aiming to increase to 20 minutes, if I am able, but I understand that 10 minutes a day is sufficient for this type of exercise. My blood pressure is almost always good (e.g. 120/70), I do not have heart disease, asthma, or diabetes, and I am generally in good health. I am female, about 5 4 , weigh about 166, and have a borderline BMI. Thank you very much for your kind attention.