Patients clenched fist no strength, mainly seen in acute cerebrovascular disease, cervical disc herniation, motor neuron disease, as follows: 1, acute cerebrovascular disease: patients are an acute onset of clenched fist weakness, accompanied by limb numbness or have ipsilateral lower limb weakness, consider the presence of acute cerebrovascular disease, the need for cranial CT, magnetic resonance examination, to understand whether there is an acute cerebral infarction, cerebral hemorrhage. 2, cervical intervertebral disc The patient has no strength to clench the fist, accompanied by numbness of the upper limbs, and limited neck movement, and also to do cervical magnetic resonance examination to understand whether there is cervical disc herniation. 3, motor neuron disease: the patient has no strength to clench the fist, accompanied by hand muscle atrophy, and the disease is relatively long, need to carry out electromyography, cranial and cervical magnetic resonance examination, and lumbar puncture examination to clarify whether there is motor neuron disease.