Effects of Flexible and Semirigid Knee Braces on Meniscal and Ligament Loading During Landing Impact

Knee braces are widely used to protect against injuries during landing impact, but their effects on the mechanical responses of internal knee tissues remain unclear. In this study, landing impact models incorporating flexible and semirigid knee braces were developed using an established human body finite element model. Model evaluation was based on volunteer measurements of ground reaction force and lower limb kinematics. The effects of brace type and landing velocity on lower limb joint motion and the mechanical responses of the menisci and major knee ligaments were then examined. Knee braces had limited effects on peak ground reaction force, primarily altering joint motion and internal tissue responses during the unloading phase. Both brace types reduced meniscal compressive stress during the unloading phase and peak medial collateral ligament tensile strain, with comparatively small effects on peak strain in the other knee ligaments. As landing velocity increased, initial impact loading contributed more to the peak medial meniscal compressive stress and peak anterior cruciate ligament tensile strain. This limited the attenuation of these peaks by the braces. The biomechanical effects of knee braces therefore depended on loading phase, landing velocity, and tissue type.