6 months back I went for a tracking and while climbing down a ladder, I placed my left leg a bit too fast and heavily which caused a slight pain the left knee. After that I have had occasional pains in left leg when I climb stairs faster or in certain unexpected situations. When consulted to an orthopedic, he said it's common at my age which is 28, and that the knee gel kind substance would regenerate automatically. But I am having glucosamine tablets for past 2 weeks and the pain is still there. 1, will the pain go away or will it stay and become rheumatoid arthritis as I age? 2, I am doing aerobics alongside, which I doubt if it deprives the regeneration of the knee gel like substance? Should I completely avoid doing heavy exercises or taking stairs or sitting on the floor cross legged?