Cardiac surgery patients often present with multiple comorbidities,the risk of periop-erative complications and the complexity of postoperative rehabilitation have significantly increased,posing higher demands on comprehensive perioperative management.Preoperative exercise pre-reha-bilitation,as a multidisciplinary collaborative intervention strategy,has been demonstrated to signifi-cantly improve the clinical prognosis of patients undergoing elective cardiac surgery by enhancing their cardiopulmonary function,muscle strength,and overall physiological functional reserve,thereby in-creasing the body's tolerance to surgical stress.Although phase-specific research achievements have been made domestically and internationally in the field of exercise pre-rehabilitation,its standardized implementation and clinical translation on a global scale still face numerous obstacles,necessitating systematic review and in-depth exploration.Therefore,this study aimed to conduct a systematic re-view of the intervention protocols,clinical efficacy,safety,and feasibility of preoperative exercise pre-rehabilitation in patients undergoing elective cardiac surgery,with the goal of providing theoretical evidence and practical references for optimizing perioperative management pathways and promoting the implementation of enhanced recovery after surgery concepts.

【Objective】 To explore the correlation between the falling height and the fracture degree of skull and extremity bones. 【Methods】 A total of 66 cases of high falls with no-obstacles and hard contact surface that occurred in Yuexiu District of Guangzhou from June 2014 to May 2018 were collected, in which only fractures of skull and(or) extremity bones were observed. Of these cases, 1 to 3 points were assigned to linear fractures, comminuted fractures, and open fractures respectively in reference to "Human Injury Degree Appraisal Standard" , and each site of fractures could receive a unique maximal abbreviated injury scale(MAIS) value from Abbreviated Injury Scale(AIS) 2005. The sum of unique MAIS to different fracture sites indicated the total severity of those fractures(FT). Multiple linear regression analysis was performed on the falling height(Y) and FT of skull and extremity bones, age and gender. 【Results】 Age was an influential factor in the classification and quantification of fracture degree. There was a strong positive correlation between skull FT or extremity bones FT(r1 = 0.698 or r2 = 0.780) and Y, ? ? (m) = 6.660 + 2.843 × skull FT + 2.664 × extremity bones FT-0.099 × Age, R² = 0.871, SE = ±4.577 m. 【Conclusion】 Our results suggest that the total severity of skull fracturesand extremity bones fractures are two important indicators for the prediction of falling height. The mathematical model for prediction of falling height may be practical and applicable in related studies for the reason that it is confirmed in the earlier literatures.