The medical science and technology that aims at rehabilitation and serves to solve the problem of functional rehabilitation of the sick, injured and disabled is called rehabilitation medicine. Rehabilitation medicine refers to the medical discipline that takes various measures to restore or improve the function and quality of life of people with various functional disorders caused by various congenital or acquired diseases or traumas, in order to achieve the purpose of returning to society. In other words, rehabilitation medicine is a discipline that enables the sick, injured and disabled to recover physically, mentally and professionally. Its goal is to remove or reduce the functional impairment caused by illness or injury, and to help the sick, injured and disabled to recover their life and labor capacity to the maximum extent possible within their physical condition and according to their actual needs. It is an interdisciplinary and marginalized discipline that interpenetrates with psychology, sociology and engineering. In foreign countries, rehabilitation medicine is also referred to as “rehabilitation” or “physical medicine and rehabilitation” (PM, R). Rehabilitation medicine consists of basic medicine and clinical medicine. Basic medicine includes the basic theories of kinesiology, neurophysiology, human development, disability, and therapy. Clinical medicine includes rehabilitation diagnostics (functional assessment) and rehabilitation therapeutics (general: specialized therapeutic techniques of rehabilitation medicine; individual: rehabilitation of major diseases). In the whole process of human beings’ struggle with diseases, the scope of diseases can be divided into three interacting and interrelated stages: the first stage is to take preventive measures to prevent diseases before they occur; the second stage is to take necessary treatment measures to relieve patients’ pain or save their lives after the occurrence of diseases; the third stage is to treat patients when the diseases enter the chronic stage or when they have sequelae, dysfunctions or disabilities. The third stage is to take medical-based measures to help patients recover and maximize their physical, mental, life and work abilities when the disease becomes chronic or when they have sequelae, dysfunction or disability. These three stages are commonly referred to as preventive medicine, clinical medicine and rehabilitation medicine. Rehabilitation medicine is mainly for the third stage of human beings’ struggle against diseases, so it is also known as the third medicine.