I have slight arthritis in my knees, but it did not bother me last season, when I skiied more vertical feet than any year in the last 30. I put a dollar store stretch thing on my knees and I take some Aleve when I ski, but no pain or discomfort.
This spring though, my right knee got very sore after moderate bike riding. Most years I try to ride 1000 miles and this year barely 300. Going down stairs seems to offer the most discomfort. I am 59 but not overweight and in decent shape.
One unnecessary recent complication, was a bicycle fall which fractured my femur, but that is 98% healed. I have done specific exercises to strengthen the injured leg, which worked fine, but the knee on the non-injured leg is now worse than ever.
Any suggestions for exercises for the leg. Right now I cannot do squats, and in fact I can't get out of a chair without using my arms.