If the ankle becomes sore and tender, it may be caused by the following reasons: First, over fatigue, which is common when the patient walks long distances, runs, or does excessive exercise for the lower limbs, which may cause excessive fatigue of the muscles and tendons around the ankle joint, and then the patient will have the above symptoms. Secondly, it is common for patients to have arthritis of the ankle joint, such as traumatic arthritis or osteoarthritis, which may lead to soreness, pain and weakness due to abnormal friction of the joint in the process of its activity. Thirdly, it is common for patients to have osteoporosis, and once they have such diseases, they will have symptoms of joint soreness and weakness in the lower limbs and lower back.