Objective To study and analyze the theory, policy framework, and core content of physical activity policies and physical activity guidelines. Methods Using a policy research and content analysis approach and the theory of the six components of World Health Organization (WHO) health service system, we specifically analyze the theory, framework, and core content of WHO Global Action Plan on Physical Activity and WHO Physical Activity Guidelines. Results The Global Plan of Action for Physical Activity 2018-2030 (Action Plan) is an international policy document on physical activity issued by WHO that incorporates physical activity within the context of the seven principles of human rights, the life span, evidence-based practice, proportional universality, policy coherence and integration of health into all policies, participation and empowerment, and multisectoral partnerships into health services and social development. The Action Plan consists of four strategic objectives and 20 policy actions, covering six areas of WHO health service system, and the integration of physical activity policies into health services is of great importance in promoting the achievement of the United Nations Sustainable Development Goal 3 of universal health coverage. As a technical document for the implementation of the Action Plan, 2020 WHO Guidelines on Physical Activity and Sedentary Behavior (Guidelines) adopted the PI/ECO approach to analyze the physical activity needs of various groups of people, and provide guidelines to increase physical activity and reduce sedentary behavior for children and adolescents, adults, older adults, pregnant and postpartum women, people with chronic diseases and people with disabilities. The guidelines cover duration, frequency, and intensity of physical activity, types of physical activity, critical and important health outcomes of physical activity, and health risk prevention and related considerations. The Guidelines implement the relevant guiding principles of the Action Plan and aim to improve overall population participation in physical activity at the micro level and improve critical and important health outcomes for the overall population. Conclusion As a health and development strategy, the Action Plan promotes the integration of physical activity into the health delivery system to facilitate the achievement of the United Nations 2030 Sustainable Development Goal 3 of universal health coverage.The four strategic objectives and 20 policy actions of the Action Plan can be integrated into these six areas based on the six components of WHO Health Service Delivery System: leadership and governance, financing, human resources, service delivery, medical technology, and health information. As a technical document to implement the Action Plan, the Guidelines are based on the PI/ECO approach framework and provide guidance on increasing physical activity and reducing sedentary behavior for children and adolescents, adults, older adults, pregnant and postpartum women, chronic patients, and persons with disabilities. The core content addresses the target populations, duration, frequency, and intensity of physical activity, types of physical activity, critical and important health outcomes of physical activity, and health risk prevention and related considerations.

Objective To study the characteristics and mechanism of mine blast injury that wading in shoal of different depths through an animal model.Methods Ninety-six healthy adult New Zealand white rabbits weighing 2.19 ± 0.12kg were randomly divided into land group (n=16),limb wading group (n=16,the water depth reaching up the middle of the thighs of rabbits),and chest wading group (n=16,the water depth reaching up the thoracic xiphoid),stress test group (n=30),fake injury group (n=18).Punctiform burster was used to simulate landmine.Electric ignited the simulated mine away,causing landmine explosion injury to rabbits' one-sided hind limbs in upright state.High-speed photography was used to observe the movement of water accompanying the simulated mine explosion.Arterial blood serum markers of myocardial injury (CK-MB,cTnⅠ) and nerve injury (MBP,NSE) were detected before injury,and 3,6 and 12h after injury,and echocardiography,electrocardiography,CT,DSA and other examinations were implemented at the same time.Survival animals were killed 12h after injury for anatomy to record their injuries to the limbs and distant organs.The histopathological examination was done to define the injury characteristics furthen Results Feet and distal tibia were broken,and closed femoral fractures and arterial damage were often found away from the stump in limb wading group.This type of injury was different from the mop-like tearing tissue in the land group.Chest,abdominal organs and the brain,spinal cord injury in wading group were more severe than those in land group.There were higher incidences of chest,abdominal organs and spinal cord injury in chest wading Group.Conclusion The energy transfer of underwater explosion is affected by water depth and limbs or trunk mutually,which is an important mechanism of the complex and serious injuries in the wading group.The wading depth is an important factor affecting severity of the injury.Based on characteristics and unique mechanism of wading explosion,emergency treatment and the principle of early treatment for injury warrant further explored.