There are many reasons for the lack of strength in the feet, if it is unilateral, it may be due to lumbar disc herniation caused by sciatic nerve irritation, this weakness is often accompanied by pain and discomfort in the lumbar region, for further examination, this time you can carry out magnetic resonance examination of the lumbar spine. It may also be due to cerebral infarction caused by half of the limb weakness, this condition is often accompanied by upper limb weakness, hemiparesis, hemiplegia, hemiplegia, cranial CT examination can often be seen in the low density shadow. Of course, it may also be due to the patient’s anemia, this time the patient will feel the weakness of the limbs, if the symmetrical weakness of the lower limbs, this time to be highly suspicious, whether it is secondary to hypokalemia. Hypokalemia patients will be manifested as double lower limb weakness, walking difficulties, this time blood test can be diagnosed, when the discovery of double lower limb weakness, should actively look for the primary disease, only for the treatment of the primary disease, will have obvious effect.