A brace is an external fixation that is placed on the outside of the body and is designed to restrict a movement of the body, thereby aiding the effectiveness of surgical treatment, or is used directly for non-surgical treatment. By adding pressure points to the external fixation, it can become an orthopedic brace and be used for the correction of body deformities. Brace, also known as orthosis, is an extracorporeal support device aimed at reducing the dysfunction of the limbs, spine, and skeletal muscle system. It is used for non-surgical treatment or surgical adjunct treatment. Classification of brace: 1.Upper limb brace: elbow brace, thermoplastic plate, forearm sling; 2.Lower limb brace: long leg brace, knee brace, calf brace, thong shoe; 3.Trunk brace: neck brace, stiff waist circumference, etc. Functions of brace: 1.Stabilize joint; 2.Protect bone implant or fracture to replace weight bearing; 3.Correct deformity or prevent deformity aggravation; 4.Replace function; 5.Assist hand function exercise; 6.Supplement length; 7.Temporary external fixation. Brace is used for human limbs, trunk and other parts of the body, treatment of bone, joint, muscle and nerve disorders, through the role of force to prevent, correct deformity or assist the disabled limb, in order to facilitate the recovery or function of the limb or trunk.