Bending of the little finger can be caused by trauma, tenosynovitis, palmar tendon contracture, dermatoconstricture and other factors, which need to be further differential diagnosis. 1. Trauma: Trauma to the little finger can cause injury or rupture of the extensor tendon, resulting in limited extension of the little finger and constant bending. It is necessary to consult a doctor in time to clarify the situation of tendon injury, and then fixate and brake the tendon actively or repair the tendon surgically. 2. Tenosynovitis: excessive activity of the little finger can cause edema in the tendon sheath, resulting in the tendon in the tendon sheath being stuck, causing the tendon to be unable to move, and then the little finger is fixed in the bent position, and can only be restored to the activity by breaking, which can be accompanied by popping and ringing and other manifestations. 3. Metacarpal tendon membrane contracture: Metacarpal tendon membrane contracture, flexion can cause the operation of the little finger can not straighten the situation, need to consult a doctor, with a splint or support fixed in the straight position. When the contracture of the palmar tendon membrane is serious, surgical resection of the contracted palmar tendon membrane is feasible for treatment. 4. Dermatoconstricture: some children cannot straighten their little finger at all, which may be related to congenital dermatoconstricture. Dermatoconstricture leads to tightness of the local skin, and it is not possible to straighten the little finger when the joints are moving, which is often accompanied by contracture of tendons and joints, etc. When the little finger is bent, it should be treated promptly by a doctor, and the contracture should be fixed with a splint or a brace. When the little finger is curved, it is important to consult a doctor in a timely manner, so that the specialist can clarify the condition and take appropriate treatment to help improve the curvature of the little finger as soon as possible.