Numbness and stiffness in the ball of the foot may be associated with conditions such as ankle canal syndrome, diabetes, or lumbar spine disorders. 1. Ankle tube syndrome: The plantar nerve is in the ankle canal of the inner ankle. If the ankle canal is narrowed or there are lipomas or cysts in the ankle canal, the plantar nerve will be compressed, leading to numbness and stiffness of the foot. 2. Lumbar spine disease: commonly seen in lumbar disc herniation, lumbar spinal stenosis, lumbar spine fracture or lumbar spine tumor, etc., which can also lead to numbness and stiffness of the sole of the foot due to the stimulation or compression of the peripheral nerves. 3. Diabetes: If the history of diabetes is relatively long, the blood sugar is not controlled for a long time, it will cause peripheral neuropathy, which will lead to numbness and stiffness of the soles of the feet. For the phenomenon of numbness and stiffness of the soles of the feet, it is recommended to go to a regular hospital as soon as possible for a detailed examination and diagnosis, to clarify the specific causes of the disease, and to take timely and targeted therapeutic measures.