Leg joint pain can not stand up may be caused by osteoarthritis, gout, sports injuries, patellofemoral arthritis, muscle strain, rheumatoid arthritis and other diseases. 1. Osteoarthritis: mostly seen in the elderly, because after the age of the joint degeneration and proliferation, serious patients will appear joint space narrowing, joint swelling, so there will be limited joint activity, can not stand up, through the film of the knee can be found in the degree of joint lesions, to take conservative treatment or surgical methods. 2. Gout: there can be pain in the knee joints that can not be moved, usually occurring suddenly, locally there will be redness, swelling and fever, through the test of uric acid can be a clear diagnosis, the application of uric acid-lowering drugs to treat, the pain can be reduced. 3. Sports injury: such as knee ligament injury or meniscus injury can cause joint pain, joint activity is limited. 4. Patellofemoral arthritis: Patellofemoral joint degeneration, hyperplasia, cartilage wear and tear caused by the main impact on squatting activities. 5. Muscle strain: muscle strain around the knee joint, localized swelling, pain is obvious, can not stand up. 6. Rheumatoid arthritis: synovial hyperplasia, joint swelling, deformation, generally for both sides, affecting squatting activities. There are many reasons why you can’t stand up with leg joint pain, and you need to go to the hospital for a radiograph examination to make a clear diagnosis, and then further treatment for the cause.