Development of an Exosuit Knee Brace for Anterior Cruciate Ligament Injury

Abstract

The anterior cruciate ligament (ACL) is a crucial passive stabilizer of the knee joint. ACL injuries affect the anteroposterior stability of the knee joint. Many rigid knee braces with hinge designs claim to provide stabilization forces for the knee, however, current clinical practice guidelines recommend not using a functional knee brace during return to activity and return to play phases. In this study, we aimed to design a hinge-less exosuit knee brace that combines flexible materials to improve comfort at the brace-body interface while providing dynamic support forces during walking tasks using an offboard actuation system. We recruited 11 participants: 5 for design tests and 6 for walking tests. Our active exosuit knee brace was able to produce up to 88.9 N of cable force during a portion of the stance phase with a rise time of 111-150 milliseconds at different load settings and under 10N during the swing phase. Comfort scores were high (> 7) during most walking tests. The range of knee flexion was reduced by about 5 degrees when the exosuit knee brace was activated during walking, and brace migration was within 10 mm in most cases.