The reasons why patients do not have sensation in the heel are as follows: 1. Lumbar disc herniation: When the herniated disc tissue compresses the lumbar 5 sacral 1 nerve root, there is often radiating pain and numbness in the lower limbs, especially when it compresses the sacral 1 nerve root, there can be numbness and loss of sensation in the outer ankle and heel. 2. Local neuritis: Local dermal neuritis can manifest as local skin sensation 3.Ankle canal syndrome: In ankle canal syndrome, the spinal nerve is compressed at the ankle canal, which often causes numbness and sensory loss in the heel and sole of the foot.