The elbow joint is a compound joint located in the upper extremity area, between the shoulder and wrist joints, consisting of the lower end of the humerus and the upper end of the ulnar radius, which includes three joints, namely the humeral ulnar joint, the humeral radial joint, and the proximal radial ulnar joint. The humeral-ulnar joint is composed of the humeral glide and ulnar glide notch, the humeral-radial joint is composed of the humeral tuberosity and the radial articular recess, and the proximal radial-ulnar joint is composed of the radial circumferential articular surface and the ulnar radial notch. These three joints are encapsulated in a single joint capsule, which constitutes the elbow joint. The front and back walls of the elbow capsule are weak and loose, while the walls on both sides are thick and tense and reinforced by ligaments, and the thick wall of the capsule is the weakest. Usually, attention should be paid to protecting the elbow joint to avoid injury to the elbow joint, and to strengthen the muscle strength and intensity training around the elbow joint.