Ankle pain in six-year-old babies may be related to trauma, Achilles tendonitis of the foot, septic arthritis and other causes. 1. Trauma: Trauma can lead to ankle dislocation, ligament damage, soft tissue damage and other conditions, can cause the symptoms of baby ankle pain. 2. Achilles tendonitis of the foot: such as flatfoot deformity will make the pressure on the Achilles tendon increase, long time not dealt with easy to lead to Achilles tendonitis, the symptoms of ankle pain. 3. Septic arthritis: Septic infection can occur in the ankle joint, resulting in joint pain, swelling, dysfunction and other symptoms. Parents are advised to take their children to the hospital in time to clarify the cause of the disease and standardize the treatment under the guidance of the doctor to avoid delaying the condition.