Knee biomechanics during walking in individuals with anterior cruciate ligament repair: The role of a custom 3D-printed knee brace.

Background: Anterior cruciate ligament (ACL) injuries frequently lead to altered gait biomechanics and muscle activation patterns, increasing the risk of osteoarthritis. Knee braces are commonly used to address these issues although a lack of consensus remains regarding their clinical benefits. The most recent 3D-printed braces, lighter and personalized, could improve rehabilitation.

Objectives: To evaluate the effect of a novel custom-made 3D-printed knee brace (Provoke™) in individuals after unilateral ACL reconstruction during walking. The brace incorporates an asymmetrical hinge system aimed at stabilizing the knee joint while minimizing compensatory movements.

Methods: Fourteen participants with unilateral ACL reconstruction wore the Provoke™ brace while walking at comfortable and fast paces. Knee kinematics and kinetics and muscular activity (rectus femoris, vastus medialis, and semitendinosus) were assessed with and without the brace. Nonparametric paired t tests were used to assess the biomechanical effect of the brace.

Results and conclusions: The Provoke™ brace improved knee kinematics, facilitating a more neutral knee position by reducing valgus angles (-1.95°) and increasing flexion angles (+1.14°). In addition, it enhanced muscle activation, particularly of the rectus femoris, suggesting improved quadriceps function. Overall, the Provoke™ brace effectively improves knee function and reduces muscle imbalances in individuals undergoing ACL reconstruction. It may help prevent further injury and reduce the risk of post-traumatic osteoarthritis development. The long-term effects of brace use in ACL rehabilitation must be investigated.