The anterior cruciate ligament (ACL) is an important ligament present in the knee joint giving much needed stability to the joint. The ACL prevents anterior (forward) motion of the lower leg with respect to the upper leg. Like any other ligament the ACL can be ruptured leading to instability in the knee joint. This increased instability and motion of the bones increases the risk of osteoarthritis (knee arthritis) progression in the patients due to the strain on the underlying structures. Reconstructive surgery and rehabilitation are some of the techniques used to improve the stability of ACL deficient patients. Knee braces are another means of improving the stability of the knee: however, the efficacy of these braces with regards to the effect on the underlying passive structures is not entirely known. MR imaging is required to view the underlying structures, but these limit the design of most braces.
This thesis is aimed at creating a knee brace implementing soft robotics to recover the instability caused due to an ACL rupture. A literature survey on the biomechanics of the knee joint following an ACL rupture, as well as clinical methods of reducing the effect is studied. A knee brace available in the market is used and we integrate pneumatic artificial muscles (PAM) in this knee brace. The knee brace will be used to assist the surrounding muscles to reduce the instability of the joint. An EMG study is performed on healthy subjects to check for a reduction in muscle activity during walking and a seated hamstring curl exercise.