Knee Kinetics Responses to Frontal Impact with Active Muscle Function During Vehicle Crash

Abstract

Knee joint injury especially under bending and rotation is a seriously outcome of lower limb injuries in car frontal accident. Due to the anatomical structure, knee is observed primarily in injuries of ligaments and muscles especially in extension or bending condition. This study aims to simulate changes of knee injuries among lower extremities under the load impact environment caused by the functionality of active muscle during the emergency braking which is observed in most of crash accidents. This is a full-scale lower extremities injury study combined with a market sold vehicle. To study the injury characteristics, a simplified real car model with whole restraint systems is first established. Then the active muscle signals during braking condition were introduced to the reaction of the leg muscle groups during the loading process, in which the stress distribution will be relocated along the legs. At last, the study targets through the relationships between ligament force/moment and deflection of the knee under real body impact condition are determined. Results show that with the usage of active muscle functionality, the vulnerable area in lower limb will move to the middle of long bones and the deflections in knee joint will become larger. Meanwhile, the forces in all ligaments around the knee will relocate. The study results can explain the source of injury differences between lower limb injury in tests and that in traffic accident statistics. The models and study methods can be employed in the continuous studies of lower limb injuries during car impact.