Myofibrillar fibrillation, a phenomenon of stimulation of the anterior horn cells of the spinal cord or the motor nuclei of the cranial nerves, is a small, rapid, or peristaltic-like fibrillation within a few centimeters of the muscle belly of a piece of muscle. It is a continuous fluctuating undulation of the muscle group, caused by continuous spontaneous contraction of the motor unit. How to identify to determine whether the muscle fiber tremor? Muscle contracture: a clinical syndrome in which the muscles and the fascial fibers in the area where the muscles are located become degenerated and contracted, leading to the characteristic gait and signs of limited joint function. Myoclonus, postural deformity at the site of contracture, severe pain around the joint, skin indentation, limitation of abduction and flexion of the joints of the limbs. Muscle tension pain: a clinical manifestation of neurasthenia. Neurasthenia is a neurological disorder characterized by weakening of brain and somatic functions. It is characterized by easy mental excitement but easy fatigue, often accompanied by emotional symptoms such as nervousness, worry, irritability and other symptoms of physical dysfunction such as muscle tension pain and sleep disorders. Intentional tremor: It is a tremor that occurs during random movements. It is most obvious during purposeful movement or when the target is about to be reached, and is commonly seen when the cerebellum and its efferent pathways are diseased. Intentional tremor may not be accompanied by a decrease in muscle tone and only occurs during limb movement. Myofascial tremor: is a spontaneous discharge from one or more motor units that causes the muscle to twitch at rest in a transient single contraction, seen in a variety of lower motor neuron injury disorders and in some normal individuals. Spontaneous potentials are seen on electromyography, and nerve conduction velocities are normal. The tremor may start from the distal part of one upper limb, then spread to the ipsilateral lower limb and the contralateral upper limb, and the lips, tongue, jaw and head are the last to be involved, and the tremor may be aggravated by emotional excitement, and it stops completely during sleep anesthesia.