Lead tube-like rigidity

The increase in tonic muscle tone is seen in special tension changes in some extrapyramidal diseases. The increase in muscle tone is selective. The upper limbs are mainly adductor, flexor and pronator, and the lower limbs are dominated by increased extensor muscle tone. The resistance of patients with passive exercise is generally less than that of spastic, but it has nothing to do with the length of the muscle, that is, the contracted shape, and there is no difference between the extensor and flexor muscles. No matter what the speed, amplitude and direction of the action, they will all encounter the same resistance. This increase in muscle tone is called plumb rigidity.