Arm muscle weakness is commonly caused by the following reasons: First, serious cervical spine disease, such as cervical spondylosis, cervical disc herniation, cervical stenosis, cervical instability, etc., due to nerve compression, the muscles of the upper limb lose innervation, muscle weakness will occur, accompanied by numbness, or even pain; Second, upper limb diseases, such as periarthritis of the shoulder joints, elbow joint osteoarthritis, can lead to muscle weakness around the joints. Second, upper limb diseases, such as periarthritis of the shoulder and osteoarthritis of the elbow, can cause the muscles around the joints to weaken significantly, and the patient is weak at work, and muscle atrophy is usually more obvious; third, upper limb traumas, such as dislocation of the shoulder joints and fractures of the upper limbs, which require prolonged braking, and the lack of rehabilitation training after braking can also lead to the symptoms of temporary weakness of arm muscles.