Abstract
There is a high risk of serious injury to the lower extremities during a human drop landing. Prophylactic knee and ankle braces are commonly used to reduce injury by restraining the motion of joints. However, braces that restrain joint range of motion (ROM) may have detrimental effects on the user’s kinematical performance and joint function. The present study aimed to propose a novel set of double-joint braces and to evaluate its protective performance in terms of the ankle and knee. Accordingly, the finite element method was performed to investigate the biomechanical responses of the ankle and knee in braced and unbraced conditions. The results showed that the semi-rigid support at the ankle joint can share the high impact force that would otherwise be inflicted on one’s lower extremity, thereby reducing the peak stress on the inferior articular surface of the tibia, menisci, and articular cartilages, as well as the horizontal force on the talus. Moreover, with knee bending, the elongated spring component at the knee joint can convert the impact kinetic energy into elastic potential energy of the spring; meanwhile, the retractive force generated by the spring also provides a more balanced interaction between the menisci and articular cartilages. This biomechanical analysis can accordingly provide inspiration for new approaches to place human lower extremities at lower risk during landings.
Highlights
During a jump landing, the lower extremities are most vulnerable to injury resulting from the excessive vertical ground reaction force [1]
The vertical ground reaction force (vGRF) experienced by the musculoskeletal system are determined by various biomechanical factors such as jumping height, landing technique, wind speed, and ground stiffness [2], they are always several times the body weight (BW) [3,4]; in a 1.2 m half-squat landing, it can be as much as 14.7 times the BW [5]
Existing prophylactic knee and ankle braces, designed to reduce lower-limb injuries during landing due to the high GRF, work primarily by restraining the joint range of motion (ROM); this protective approach is still controversial in consideration of the negative effects on joint function
Summary
The lower extremities are most vulnerable to injury resulting from the excessive vertical ground reaction force (vGRF) [1]. The high impact forces are transmitted upward from distal to proximal, and in this process, multi-joint motion, joint muscles, and articular soft tissues are required to absorb the impact energy It is, not surprising that the ankle, foot, and knee are the body parts at most risk of injury during landing [6], because the ankle and foot, as the largest weight-bearing parts in the human body [7], are the first to be struck, and the knee exhibits a vital physiological structure of energy absorption, especially the meniscus, articular cartilage, and ligaments, as well as a larger joint range of motion (ROM). As stated above, during drop landing, the mechanism of injury and the injury pattern have been investigated sufficiently, and scientists have drawn similar conclusions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
