The bone below the knee is the location of the proximal tibia, tibial plateau, tibial tuberosity, for the reasons that lead to pain, as follows: first, tibial tuberosity, patellar tendonitis: if the place of the tibial tuberosity obvious pressure pain, swelling, this situation may be tibial tuberosity, patellar tendonitis, is because the patellar tendon is often with the tibial tuberosity of the tibia pulling, especially often to do strenuous exercise of the knee is more common in the population, which leads to pain in the tibial tuberosity periosteum place. This leads to aseptic inflammation of the periosteum of the tibial tuberosity, resulting in pain. Second, traumatic fracture: the most common is tibial plateau fracture. Third, the proximal end of the tibia has grown a swelling: common is a bone cyst or malignant tumor, you can take a local X-ray to clarify the diagnosis.