Weakness and tenderness of the feet may be caused by calcium deficiency, anemia, lower limb injury, spinal cord nerve injury and other reasons. 1. Calcium deficiency: when there is weakness and tenderness of the feet, it may be caused by calcium deficiency. The daily needs of the human body are generally composed of various trace elements, and when the body is deficient in calcium, it will lead to weakness and weakness of the legs and other symptoms. 2. Anemia: the main component of blood is red blood cells, when there is a lack of red blood cells, it will lead to a lack of oxygen. At this time, there will be weakness and tenderness of the legs. 3. Insufficient blood supply to the lower limbs: If the local trauma to the lower limbs or arteriosclerosis occlusive disease of the lower limbs leads to insufficient blood supply to the lower limbs, then weakness and tenderness of the feet may occur. 4. Spinal nerve injury: when the spinal nerve injury caused by prolonged compression (such as lumbar intervertebral disc herniation, lumbar spinal stenosis, etc.) can also cause weakness and tenderness of the feet. It is suggested that there may be other causes of weakness and tenderness (e.g. osteophytes). If these symptoms persist for a long period of time, the patient should go to the hospital as soon as possible to find out the cause and get treatment.