The sensory nerves in the fingers are nerve roots that branch out from the cervical spinal cord and form the brachial plexus nerve in the cervical axilla, then branch out into the radial and ulnar nerves, which lead to the upper arm and distribute peripheral nerves to the hand and fingers. If the nerves in these areas are damaged, inflammation or tumors can cause abnormal sensation and finger numbness and pain. Injury to the median nerve, ulnar and radial nerves in the proximal forearm and elbow can cause dysfunction in finger flexion and extension; hand trauma often involves the distal forearm and wrist, except for the radial nerve, which only causes hypesthesia in the tiger’s mouth, and injury to the median and ulnar nerves can cause dysfunction in the internal muscles of the hand and important sensory impairment in the hand. The examination methods for thumb-index finger pinch dysfunction are: 1.Thumb short extensor muscle strength test. 2.Thumb to palm muscle strength test. 3.CT examination of bone, joint and soft tissue.