1.Definition In the special isometric trainer to obtain a constant angular velocity, that is, the training of constant speed of movement, but the resistance encountered with the degree of force and change, in order to keep the muscle tone of the athletic limb in the best state of muscle training methods. 2, indications and contraindications (1) indications: muscle disuse atrophy caused by braking, reduced movement or other causes, muscle atrophy caused by muscle lesions, muscle dysfunction caused by neuropathy, muscle weakness caused by joint disease or injury, muscle dysfunction, muscle training of healthy people or athletes. (2) Contraindications: joint instability, new fracture or fracture not completely healed, acute inflammation or infection (redness and swelling), severe pain and hematoma during joint activity or muscle extension, bone and joint tumor, poor general condition, and unstable condition. 3.Equipment and appliance isometric training device. 4.Operating methods and steps (1) Before training: Turn on the machine and install the corresponding training equipment according to the training requirements. (2) Position the patient and fix the patient well. (3) Joint movement angle setting: Usually the full joint movement angle can be set. For muscle, tendon, ligament healing early, post-operative joint or joint lesion, it is appropriate to choose the limited joint movement range. (4) Training methods: divided into isometric centripetal and isometric centrifugal training. Movement speed: usually includes 60, 120, 180 degrees/second or 60, 120, 240 degrees/second, and the maximum speed can be increased to 720 degrees/second according to the training needs. The training program can also be set to 8 to 10 speeds, set in 20 or 30 degree/sec increments or decrements. (5) The number of training: It is recommended to use 10 repetitions of each exercise speed state, but also according to enhance muscle strength or develop muscle endurance to determine the exercise intensity, interval time and frequency of training. 5, precautions (1) before the maximum load of equal speed exercises, should be carried out low and medium load exercise. (2) full-angle range of motion should be preceded by small-angle activities. (3) Centripetal isokinetic exercise should be performed before centrifugal isokinetic exercise to allow the patient to better grasp the exertional skills, because the speed of movement during centrifugal exercise often comes from the robotic arm rather than the patient himself. (4) Refer to “Isotonic muscle training” for other considerations.