On the last day of 2008, a patient with a chronic ankle injury came to the clinic. The patient, a senior in medical school who loves sports, had an acute external ankle sprain four years ago, and the student complained that he could hear at least 2 very crisp sounds at that time. The student complained that he could hear at least 2 crisp sounds at that time. He did not receive any formal treatment after the injury. The patient still wore ankle brace and high-top basketball shoes for the past four years, but he felt soreness in his outer ankle for several days after exercise. He had been to some orthopedic departments and Chinese medicine injury departments, but did not see any improvement. He was recommended by his medical school teacher to come to our rehabilitation clinic. In the past 2 years, we have treated a number of cases similar to the one mentioned above, mostly young people who love sports and have not been left with chronic joint instability and pain due to an acute injury. After several orthopedic, injury, and physical therapy departments to receive local seal, Chinese herbal medicine, NSAID drugs, etc., although the pain can be temporarily relieved, but can not return to the pre-injury sports level. Ankle braces and high-top sneakers became their protective gods. These patients began to run to our orthopedic clinic, and our orthopedic surgeons were so aware of the technical tool we have for orthopedic rehabilitation, therapeutic exercise, that they handed the patients over to us. Since almost all such patients have external ankle problems, we first do two special tests: 1. Anterior Drawer Test – to determine the laxity of the anterior talofibular ligament. 2. Talar tilt test – to determine the joint injury of Anterior Talofibular ligament and Calcaneofibular ligament. Static stability structure of the joint – Ligament injury leads to instability of the joint, and we hope to improve the dynamic stability of the joint by strengthening the strength of the muscles around the joint. This principle is often used to target hamstring/quads strengthening after ACL/PCL injuries of the knee. In fact, the same theory can be applied to ankle instability. In patients with external ankle instability, the patient is prone to inversion injury during sports, so we need to strengthen the external rotation muscle group. The realization of this idea depends on our orthopedic rehabilitation Biodex isokinetic dynamometer. In fact, we have been able to return many young people with ankle sprains to the sport they love through the biodex ankle isometric training over the past 2 years. Finally, it is important to note that isometric ankle extensor strength training is open chain. To increase joint stability, closed chain training is indispensable. This requires a device called a BAPS plate. Of course, if we don’t have a BAPS board, we have to make do with a balance board. Obviously, because the former can adjust the ROM and load, its training safety and effectiveness is much stronger than the balance board. Unfortunately, this good thing has not seen in the country.