Arthritis and patellofemoral pain syndrome are two causes of knee stiffness, according to the Arthritis Foundation and the American Academy of Orthopedic Surgeons. Pain at rest indicates arthritis, and pain in the front of the knee right below the kneecap indicates patellofemoral pain syndrome.
The Arthritis Foundation and the AAOS both state that ice can provide pain relief. Nonsteroidal anti-inflammatory drugs help treat both conditions by reducing inflammation. Osteoarthritis is a common arthritic condition affecting the knee, and it is caused by a breakdown in the cartilage lining the bones of the knee. Patellofemoral pain syndrome results from overuse, improper mechanics or form, or poor patellar alignment. This condition is treated with physical therapy in some cases.