Myotonia is the force generated by the mutual traction of muscle cells, and the tension of the muscle in a resting and relaxed state is called myotonia. Low muscle tone means that the resistance encountered by the muscle group when doing passive activities during muscle relaxation is reduced, and the muscle lacks swollen muscle belly and normal toughness within the muscle and is flaccid. The clinical manifestations generally vary depending on the site of damage: in damage to the anterior horn cells of the spinal cord, there is muscle weakness, atrophy, and no sensory disturbance by phase distribution, with muscle fiber tremor. In the case of damage to the proprioceptive fibers of the posterior cord of the spinal cord or peripheral nerves, peripheral nerve damage is accompanied by muscle weakness, atrophy, and sensory disturbance. The causes of hypotonia are also related to cerebellar diseases, such as cerebellar hemorrhage, cerebellar degeneration, cerebellar ridge blockage, and occupational lesions of the cerebellum. Similar symptoms can occur when the body is deficient in certain trace elements. For example, when the body is deficient in calcium, muscle spasms and tension may occur, and hypotonia may also occur. Therefore, when analyzing the causes of hypotonia, it can be summarized that it is generally caused by lesions of the musculocutaneous nerves or the lower motor neurons of the spinal cord, and cerebellar lesions can also produce abnormally low muscle tone.