The tendon pain on the outside of the knee may be caused by strenuous exercise, arthritis and other factors, and it is recommended that the patient consult a doctor for examination in time. 1. Strenuous exercise: overwork or strenuous exercise in a short period of time in daily life may lead to muscle strain on the outside of the knee, resulting in tendon pain, which can be relieved by proper rest or massage. 2. Arthritis: usually due to inflammation, infection, trauma and other factors leading to inflammatory lesions in the joints, if not treated in time, may lead to the phenomenon of radiating pain in the surrounding soft tissues, the patient can follow the doctor’s instructions to use glucosamine, bisacodyl, and other medications to carry out treatment. Patients with severe joint disorders can be treated with surgical methods such as arthroplasty. There are many other causes of tendon pain on the outside of the knee, such as meniscus cysts and other diseases, it is recommended that patients seek timely medical examination to clarify the cause of the disease and then targeted treatment.