An understanding of knee dynamics is vital to treat neurological and musculoskeletal conditions that affect the lower extremities and achieve peak performance from athletes. To obtain and analyze kinematics and kinetics of the knee, clinicians and athletic trainers require accurate, accessible measurement devices. To assess the functionality of one such device, the Mizzou Knee Arthrometer Testing System (MKATS), dynamic motion studies were carried out on healthy, ACL deficient, and patellofemoral pain populations. To assess the validity of the MKATS, the device output was compared to data collected using a SimVitro robotic manipulator. Through this process, discussions with clinicians, technicians, and participants resulted in modifications to both the software and hardware of the device to improve fit and usability. The following thesis summarizes the findings of the dynamic and cadaver motion studies, and the modifications to the device. We found decreased flexion and internal rotation at specific points (p [less than] 0.05) of the cycle for all dynamic activities for both clinical groups compared to the healthy control group. Due to unperceived amounts of skin artifact and joint laxity, the results of the cadaver study were inconclusive. The MKATS was able to accurately detect kinematic differences in the live study groups and has promise as a useful tool for orthopedic surgeons, physical therapists, and athletic trainers to screen for abnormal dynamics and track treatment success. Further studies utilizing computed tomography on live participants will be needed to further validate the MKATS. The development of such devices is crucial to improve the quality of advice from healthcare and athletic performance specialists.

Following knee surgery, clinicians have traditionally used visually rated or time-based assessments of lower extremity movement quality to measure surgical outcomes, plan rehabilitation interventions, and measure success. These methods of assessment are prone to error and do not fully capture a patient's inefficient movement patterns post surgery. Further, currently available systems which objectively measure kinematics during these tasks are expensive and unidimensional. For these reasons, recent research has called for the development of objective and low-cost precision rehabilitation tools to improve clinical measurement of movement tasks. The purpose of this article is to highlight two such tools and their applications to knee surgery. The systems highlighted within this article are the Mizzou Point-of-Care Assessment System (MPASS) and the Mizzou Knee Arthrometer Testing System (MKATS). MPASS has demonstrated high levels of agreement with the gold-standard Vicon system in measuring kinematics during sit-to-stand (R > 0.71), lateral step-down (intraclass correlation coefficient [ICC] > 0.55, apart from ankle flexion), and drop vertical jump tasks (ICC > 0.62), as well as gait (R > 0.87). MKATS has been used to quantify differences in tibiofemoral motion between groups during lateral step-down, step-up-and-over, and step-up/step-down tasks. Objective measurement of clinical tasks using portable and inexpensive instruments, such as the MPASS and MKATS, can help clinicians identify inefficient movement patterns and asymmetries which may damage and wear down supporting structures within the knee and throughout the kinetic chain causing pain and discomfort. Identifying these issues can help clinicians to plan interventions and measure their progress at a lower cost than currently available systems. The MPASS and MKATS are useful tools which have many applications to knee surgery.