Characteristic research of lower extremity injuries in elderly pedestrians during collisions.

Purpose: The aim of this research is to study the trend of pedestrian lower extremity injuries during vehicle-pedestrian collisions.

Methods: In this study, pedestrian's age, collision angle and pedestrian's position are considered influencing factors. Nine experiments using a novel lower extremity mechanical model are designed with the orthogonal experiment method.

Results: Under the same collision angle, collisions in the left and right positions caused more serious tibia injuries than the middle position. As for the collision angle, the tibial injury at +45° is more significant than the tibial injury at -45°, and the injury of oblique collisions is slightly greater than that at 0°. Moreover, tibial injury is more sensitive to research variables than femoral injury. When the collision angle and position are changed, the difference ratio of tibia stress is by 483.2% higher than that of femur stress. The axial force and bending moment of the quadriceps tendon in the left-position collision reach peak values, which are 3.83 kN and 165.98 Nm, respectively. The peak quadriceps tendon axial force is captured with the collision angle of -45°, and the peak quadriceps tendon bending moment is obtained with a collision angle of +45°.

Conclusions: The effects of differences in impact position and angle on lower extremity injury in the elderly were analyzed, and the results of this study can be used as a reference for research on lower extremity protection.