Knee pain when running and going up stairs

Patient: While in the middle of half marathon training, I went snowboarding and sustained a knee injury but not from one specific incident, but maybe overuse?. Initially it was popping all the time and while normal activities were pain-free, stairs and attempting running hurt like the dickens! After spending 8 weeks run-free, I attempted today. Running uphill was cake while running downhill hurt bad. And now it is popping again! I have been unable to straighten my knee this whole time, but the only time I have pain is when running. I know my walk isn’t quite right as well, but since it doesn’t hurt I can’t figure out what I am doing wrong. The problem is directly under my knee cap. I’ve worn and do wear a brace, but I can’t discern any real benefit yet. What is wrong? What should I do?

Doctor: The Knee pains you described it is the most common presentation of patellofemoral syndrome in young and active people. The pain typically is located behind the kneecap and often shows during activities that require knee flexion and forceful contraction of the quadriceps (i.e., during squats, ascending/descending stairs or pendants or even running). Pain may be worsen by sitting with the knee flexed for a long period of time, such as while watching a movie, hence leading to the terms “theatre sign” and “movie-goer’s knee.” The causes are diverse: Overuse (repetitive use or activity), overloading, and misuse of the patellofemoral joint. The suggested strategy for conservative treatment should be as follows: Physical therapy program (exercises and pain control with TENS, ultrasound, ice packs after exercises), anti-inflammatory medication (i.e.: “Aleve”, “Advil”), educate you about which activities avoid because those can aggravate patellofemoral syndrome. Also, and very important, remark the need for extended adherence to the exercise regimen. The physical therapist should teach you  a home exercise program that you can easily follow consistently to strengthen your quads and the rest of the legs muscles. Allow time for these conservative measures (i.e.: exercise program) to have an effect , usually 4-6 weeks is adequate for some resolution of symptoms.