Knee Exoskeleton- Review of Knee Musculature and Exoskeleton Device Proposed Design

A review of the lower extremity musculature surrounding the knee is provided as well as a lower extremity knee exoskeleton design proposed. The review provides a general understanding of the body m usculature around the knee with an emphasis on the geometry of the musculature. The proposed device design uses the reviewed musculature geometry as the basis for the design. In function, the proposed device focuses on creating a mechanical advantage at the knee joint which assists individuals who are suffering temporarily, or permanently, from quadriceps weakness or atrophy brought on by Osteoarthritis, Patellofemoral Pain Syndrome (PFPS), or other knee conditions. The design was analyzed over flexion angles between 0 to 90 degrees. Physical testing, as well as linear and nonlinear model calculations, were performed to determine the design’s strength capacity and function. The resulting force and momentum values of the device were compared to those characteristics of a healthy leg (a hip-to-knee length of 18 inches and a body weight of 180 pounds as the standard dimension and weight for testing). From the comparison data, the proposed device was found to be significantly similar to the body’s calculated maximum applied moment. Additionally, the comparison of the curves of the moment versus flexion angle for the device and body showed the linear model case to not be similar to the body while the nonlinear model case was similar to the body.