The hand shape after ulnar nerve injury, due to different injury sites, resulting in different ranges of muscle paralysis, the corresponding hand shape also has some differences. 1. When ulnar nerve injury occurs above the level of the wrist joint, the ring and little finger are affected by the action of the extensor tendon, which puts the metacarpophalangeal joint in a state of hyperextension. At the same time, the deep flexor muscles of the ring and little finger have not yet lost their function, which continues to have an impact on the interphalangeal joints of the ring and little finger, and the interphalangeal joints are flexed under the action of the tension, which leads to an obvious claw deformity in the hand. 2. When ulnar nerve injury occurs above the level of the elbow joint, it affects the deep finger flexors and wrist flexors on the ulnar side, resulting in muscular flexion disorders, with the ulnar side of the wrist unable to flex, the ring finger and the distal side of the little finger joint unable to flex, and the distal side of the little finger having difficulty in flexion and extension, accompanied by dysfunction of the intramuscular muscles of the hand and the 3rd and 4th earthworm muscles. Because of the high plane of injury, the medial head of the bunion and flexor digitorum profundus muscles were paralyzed, and the patient could observe a large depression, which often appeared in the interphalangeal area near the intermetacarpal side. The patient has a mild claw-like deformity in appearance.