Geometry and mechanism of attachment
The design of the knee brace is crucial to its effectiveness, particularly regarding the geometry and attachment mechanism. The brace attaches to the leg through carefully designed femoral and tibial supports, ensuring that it provides stability while being comfortable for the user. Tibial and femoral condylar padding enhance the contact area, improving the brace's fit and effectiveness in distributing forces across the knee joint. The attachment mechanism relies on strapping, which can be elastic or inelastic. The number of straps and their arrangement are critical factors in how the load is distributed; wider straps offer greater leverage and better control. Patient compliance, influenced by how the brace fits, feels, and functions, is also an important consideration. A well-fitting brace encourages regular use, increasing the chances of successful rehabilitation or injury prevention.

Material Selection
Material selection is another crucial aspect of the knee brace design. Traditionally, braces were made from heavier materials such as steel, plastic, and fabric. However, modern braces utilize lightweight composite materials like carbon fiber and aluminum, significantly reducing the brace’s weight to under one pound. These advancements allow for reduced energy expenditure, making the braces more suitable for athletic use while maintaining durability and support. The lightweight nature also enhances the user experience, providing a better fit and making the brace more comfortable for prolonged use.

Hinge Design
The hinge design is a critical feature in the functionality of the knee brace. For the brace to mimic natural knee movement, the knee hinge must recreate polycentric rotation and femoral rollback, essential for normal knee function. Simple hinges are insufficient because they fail to replicate natural knee kinematics. Polycentric hinges, which are often incorporated into functional braces with dual hinges, more accurately follow the natural movement of the knee joint.  To ensure optimal brace performance, the placement of these hinges relative to the femoral condyles must be precise, allowing the brace to support the knee effectively throughout its range of motion.