Bone pain below the knee may be caused by trauma, knee osteoarthritis, lumbar disc herniation and so on. 1. Trauma: Trauma is mainly caused by external force, such as falling, heavy objects, etc., which directly affects the area below the knee, and under the stimulation of external force, it causes the soft tissue below the knee to be damaged, thus resulting in bone pain below the knee. 2. Knee arthritis: Knee arthritis may be caused by joint osteophytes, the knee in the inflammation of the stimulation, or in the friction of osteophytes stimulate the pain sensory nerves, thus causing bone pain below the knee. 3. Lumbar disc herniation: Lumbar disc herniation may be caused by long-term incorrect sitting posture, because the knee is innervated by the sciatic nerve, and the sciatic nerve is issued from the lumbar region, when the lumbar disc herniation stimulates the sciatic nerve, the bone pain below the knee occurs. Bone pain below the knee may also be related to chondroma and bone fracture, it is recommended to consult a doctor to confirm the diagnosis, and then carry out targeted treatment.