Objective:This study explores the biomechanical characteristics and potential sports injuries of reverse vertical jump (CMJ) in male firefighters of different grades based on spatiotemporal parameters, dynamic parameters, and kinematic parameters. Method:A total of 86 male firefighters were recruited (age: 29.01±5.11, height: 1.73±0.05, weight: 69.61±8.15, service years: 5.83±5.05, BMI: 23.36±2.31). The IMU insole was adopted as the measurement tool and the relevant index parameters were measured. SPSS29.0 was used for sorting and statistical analysis. Result:The results of some CMJ indicators of firefighters of different grades showed statistically significant differences. The right leg lift-off time of senior firefighters was lower than that of junior firefighters (P < 0.05). The flexion Angle of the left ankle landing of senior firefighters was lower than that of junior and intermediate firefighters (P < 0.05). The left leg propulsion speed of senior firefighters was lower than that of junior firefighters (P < 0.01), and also lower than that of intermediate firefighters (P < 0.05). Meanwhile, the right leg propulsion speed of senior firefighters was lower than that of junior firefighters (P < 0.05). There were statistically significant differences in the results of some CMH indicators among firefighters with different attributes. The right leg landing stability of the national team firefighters was higher than that of the professional team (P < 0.05). The commander's leg flight time, flight height, flexion Angle of the left ankle upon landing and the propulsion speed of the left leg were all lower than those of the firefighters (P < 0.05). Conclusion:As the rank of firefighters increases, their vertical jumping ability shows a declining trend. The decline of various indicators of senior firefighters (CMJ) is more obvious compared with that of junior firefighters, indicating that they have regressed in center of gravity control, strength level and joint range of motion, and have increased the potential risk of injury. The shock absorption capacity and stability of the right ankle joint of national team firefighters need to be improved more compared with those of professional team firefighters. Commanders have lower levels of center of gravity control, ankle range of motion and pushing force than firefighters, indicating a higher potential risk of injury for them during mission execution and strength and conditioning training.