The role of the latissimus dorsi muscle is as follows: the latissimus dorsi is the largest flat muscle, located in the lower part of the back and the posterior lateral side of the thorax, starting from the tendon membrane, from the spinous process of the lower six thoracic vertebrae, the spinous process of all lumbar vertebrae, the median sacral crest, and the posterior part of the iliac crest, etc. The muscle bundle is concentrated outward and upward, ending at the humeral tuberosity with the flat tendon. The main function is to make the humerus inward, rotate inward and extend backward, and to do pull-ups when the upper limb is raised and fixed. The latissimus dorsi muscle is often used clinically to make myocutaneous flaps or muscle flaps to repair large defects or for cardiomyoplasty, which does not have a serious impact on normal function. The muscle strength and intensity training should also be strengthened in order to maintain the normal physiological curvature of the patient and to avoid overexertion of the back.