The pain in the lateral tendons of the knee may be caused by the following reasons: 1. The patient has previously played strenuous sports, resulting in ligament strains or muscle damage, which can lead to pain in the lateral tendons of the knee. 2. The patient has been engaged in physical labor for a long time, resulting in tremendous pressure on the knee, and the tendons on the outside of the knee are overly squeezed and damaged, which can lead to pain. 3. 4. It is possible that the patient has a herniated lumbar disc, which causes the patient’s nerves to be compressed and the nerves on the outside of the knee to become painful due to compression, which in turn leads to tendon pain. After this condition, it is recommended that the patient take anti-inflammatory, analgesic and other steroidal anti-inflammatory drugs, the situation is serious, it is recommended to go to the hospital for examination, it is best to do X-ray or MRI, with the physician for treatment.