About a week ago I started experiencing anterior knee pain when either jumping or squatting. I did not have any swelling, catching, soreness, or discomfort besides when jumping or squatting. Sitting for long periods of time is not a problem, nor is straightening the leg and putting a lot of weight on it (for example, standing straight with weights and balanced on the bad leg).
Since I hadn't noticed any issues with it recently I tried putting some weight on it. I bent my leg to about 45 degrees with all my weight on it and with my shin perpendicular to the floor and it was fine. I then leaned forward a little so that my knee was no longer perpendicular and I felt I very sharp and sudden pain in the center of the knee cap. Again no swelling or discomfort other than that sharp pain and no lasting discomfort. I can turn, twist, bend, kneel, straighten and put my weight on the knee as long as it isn't too much weight without any pain felt.
I am about 28 years old, healthy weight, no history of knee injuries or problems and am fairly active in running, roller skating, and hiking though nothing competitive or high intensity. I did, however, run three days in a row without a resting day so that may have contributed. I have been resting the knee very well and doing light stretches/exercises each day so if it still seems to be an issue after this weekend I will go see my doctor.
Any ideas? I have searched for anterior knee pain and all the results seem to suggest that I would be experiencing other things (like knee catching, clicking, swelling, discomfort in other knee configurations, trouble walking up/down stairs) so I am a little lost as to what it could be.