I feel slight discomfort in my right knee when i sit with knees bent. i started taking glucosamine twice a day (1500 mg each tablet). will that help?

Movie Sign: You are experiencing a common phenomenon called "movie sign" or "theatre sign". It is associated with pain originating from behind the knee cap. The cause is typically overuse of the knee, and the treatment based on strengthening and icing. Glucosamine probably will help. Read further about treatments for "runner's knee" called chondromalacia patellae. Dr rich blake.

Inflammed tendon, or: Pain below the patella is commonly (not always) due to inflammation of the patella tendon, aka "jumper's knee" chondromalacia/arthritis is also a consideration. Typical treatment options consist of rice, antiinflammatories, physical therapy, counterbrace supports, massage, injections. Your orthopedic physician can provide a more accurate diagnosis with a physical exam and possible x-ray.