Hypertonia is characterized by increased resistance to passive movement of the limbs and reduced range of motion of the joints and is most commonly seen in cerebrovascular disease. It is characterized by increased muscle tone in the flexors of the upper extremities and the extensors of the lower extremities, and by higher resistance at the beginning and lower resistance at the end of the passive movement of the joints, which is called folding-knife hypertonia. Myotonia can be divided into five levels, and the modified Ashworth scale is currently used: Level 0: no increased myotonia; Level I: slightly increased myotonia, with a sense of “stuckness” and “sudden release” when the affected area is passively flexed or extended within the range of motion of the joint Grade I+: slightly elevated muscle tone, with a slight sensation of entrapment and minimal resistance throughout the remaining range of joint motion (1/2 the range of joint motion); Grade II: significantly elevated muscle tone over most of the range of joint motion, but the affected area moves easily; Grade III: severely elevated muscle tone, with difficulty in moving passively; Grade IV. The involved area is rigid in the flexed or extended position.