I have stiffness around the knee after sitting for a period of time. The area is lateral and may be in the area of the meniscus. I know it would be difficult to advise without a MRI, but I wanted to know your thoughts or suggestions. This has started recently and I am 59 years old, very active- weight training, cardio-walking 4 to 5 miles a day, I do not drink alcohol, or smoke anything. What do you think?