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Lower extremity injuries
Published in Youlian Hong, Roger Bartlett, Routledge Handbook of Biomechanics and Human Movement Science, 2008
William C. Whiting, Ronald F. Zernicke
Collateral ligament sprain: The knee, because of its poor bony fit, relies on ligaments for structural support. The primary ligaments are the cruciates (ACL and PCL) and the collateral ligaments, specifically the medial collateral ligament (MCL) and lateral collateral ligament (LCL). The MCL is a capsular ligament that connects the medial femoral epicondyle with the superomedial surface of the tibia. As a capsular ligament, the MCL has direct connection to the joint capsule and the medial meniscus. The LCL, in contrast, is extracapsular and connects the lateral epicondyle of the femur with the lateral surface of the fibular head.
Analysis of the influence of passenger vehicles front-end design on pedestrian lower extremity injuries by means of the LLMS model
Published in Traffic Injury Prevention, 2018
Alessandro Scattina, Fuhao Mo, Catherine Masson, Massimiliano Avalle, Pierre Jean Arnoux
At a first glimpse, it appears (Figures A8 and A9, see online supplement) that the medial collateral ligament (MCL) is the more sensitive to almost every parameter; this is expected due to the type of impact, because the MCL suffers mainly from the bending generated in the accident. This is especially evident in the case of the central position (Y = 0), whereas in the transverse offset position, the effect is more evident and more marked while varying the longitudinal offset d and the elastic moduli only. Similar considerations can be done for the posterior cruciate ligament (PCL) and anterior cruciate ligament (ACL) ligaments, whereas the lateral collateral ligament (LCL) is almost unaffected by any parameter. In particular, considering the PCL ligament, when the leg is in the central position (Y = 0), all of the parameters had a certain effect on the strain, whereas when the leg is at Y = −125 mm, only a change in the h parameter and in the elastic moduli influences the ligament strain. Moreover, the reduction of the Young modulus of the higher line seems to result in a significant reduction of strains. For the ACL ligament, reducing the p parameters also allows a consistent reduction in the ligament strains as the reduction of the elastic modulus of the higher load line does; the longitudinal offset d has instead a moderate influence.
A numerical investigation of injury mechanisms and tolerance limit of occupant femur in combined compression–bending load
Published in International Journal of Crashworthiness, 2022
Bingyu Wang, Chao Yu, Xiaoqing Jiang, Qian Peng, Yi Zhang, Fang Wang
An FE pre-processor commercial code Hypermesh version 11.0 was used to develop the current model. In the diaphysis regions, the cortical parts of the femur and tibia were meshed using deformable solid elements, while in the epiphysis regions the cortical bones were meshed using shell elements to avoid extremely low time steps. Moreover, shell elements were generated to represent the cortical bone of the pelvis and patella. All trabecular bones were meshed with solid elements based on human anatomy. The elements representing the trabecular bone were connected to the elements of the cortical bone using the share node method. The knee ligaments, including the anterior cruciate ligament (ACL), the posterior cruciate ligament (PCL), the medial collateral ligament (MCL), and the lateral collateral ligament (LCL), were represented by hexahedral elements. The lower extremity’s cartilages, menisci, and flesh were also meshed by deformable solid elements. CONTACT_TIED_NODE_TO_ SURFACE was used to connect the soft tissues with the corresponding bony structures. The skin on the exterior surface of the flesh was represented by quadrilateral shell elements. One-dimensional discrete elements were used to model the muscles to provide passive force. Considering the convergence and the minimum time step in lower extremity model, the length of a typical element was generally between 2.0 and 5.0 mm in bone, and three layers element are used to model the segment of femur and tibia shaft. The failure of bone material was based on a plastic strain, and the elements were removed when they exceeded a prescribed strain value. The resulting model consists of 97 components, 58,289 nodes, 40,155 deformable solid elements, 25,263 shell elements, and 208 discrete elements. Moreover, the element mesh qualities are refined in modified lower extremity FE model. The minimum Jacobian is 0.27, less than 3% elements with Jacobian <0.5, 8% the element aspect >15°, and the largest aspect is 57.8°. The mass of the lower extremity is 9.534 kg except for the pelvis, which is within the standard deviation of the reported mass of the six PMHS (9.1 ± 2.3 kg) [18]. The improved FE model is shown in Figure 4.