If there is frequent arm muscle jumping, part of it manifests clinically as muscle bundle tremor, which is a serious symptom of anterior horn cell injury. For example, cervical spinal cord cavitation, amyotrophic lateral sclerosis and progressive spinal muscular atrophy in motor neuron disease, cervical medullary tumors, and poliomyelitis can present with arm muscle jumping, and electromyography or cervical medullary MRI is recommended. Other conditions, such as calcium deficiency, can lead to increased neuromuscular excitability when calcium ions are lowered, which can lead to muscle twitching. Most of the time, involuntary muscle twitching in the arm will stop after a few seconds or ten seconds, or muscle twitching occurs during sleep. In fact, they are involuntary activities of innervation, feedback of nerve impulses sent downward by the brain, or appear after excessive activity or fatigue of the upper limbs, which are often physiological and actually do not need to care.