History: I am 35 years old. I am a computer programmer by profession. I have been playing badminton with intermittent breaks (1-2 year at a stretch) for about 17 years now. I have never played professionally but when I do play I play it regularly and I generally play for long hours. I have been noticing that I have tired legs for past 4 years. Initially I thought maybe it is because of my habit of sleeping late, sleeping for less than 6 hours on an average and my smoking habits. But then for past 2 years I have stopped smoking and have improved on my sleep patterns. But the problem of fatigued legs, especially my knees has been increasing. Though there is no swelling or any pain in any particular area, I do not feel the same energy in my knees like before. To sum it up, earlier I had a good jump and I used to jump and smash. But now I rarely jump. I don t plan and not jump but its just that I have involuntarily stopped jumping for hitting smashes because I don t feel comfortable with my knee. I get searing pain at certain angles. I cannot climb the stairs in a carefree manner for the fear of that searing pain at certain angles. At those angles when that pain comes, I have to balance myself using my other leg or else I feel like I could not take my body weight and will tumble. I can t remember of any specific injury or anything apart from one incident when I was trying to stamp my right foot in the ground really hard and then I felt a sharp pain in my knee. The pain was a so sharp that I got scared and stopped. But it wasn t like a continuous pain but I felt that something went wrong with my knee that day. I eventually stopped playing for about a year and then my knees felt better but then what started to happen was that my knees would feel tired about playing for about say an hour. Earlier I could easily manage it for 2-3 hours with breaks between matches and occasionally sit-outs between consecutive matches. Also now I don;t jump to smash and also I don t jump to reach to shuttles near the net from center of the court. It has affected my ability to cover court during the play.