Pain when bending the ankle may be caused by physiological reasons such as long-term strain and sprain, and pathological reasons such as gout and osteoarthritis. 1. Physiological reasons: the ankle joint is an important weight-bearing joint of the lower limbs, long-term strain may lead to aseptic inflammation around the joint, accelerated wear and tear of the joint, resulting in pain when bending; improper ankle activities or poor shoe protection may lead to ankle sprains, which may also lead to the emergence of the above symptoms. 2. Pathological reasons: people suffering from gout may also experience this symptom, mainly due to the deposition of uric acid in the ankle joint, resulting in inflammatory reaction of the joint, pain symptoms; ankle joints due to various reasons of osteoarthritis, can also lead to pain symptoms when bending, such as rheumatoid arthritis, traumatic arthritis and so on. There may be other reasons for the pain in the flexion of the ankle, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.