amputation, which includes reduced force generation at the knee and ankle, reduced control of the leg, and different mass properties relative to their intact leg. The physical change in the prosthetic leg leads to gait asymmetries that include spatial, temporal, or force differences. This altered gait can lead to an increase in energy consumption and pain due to compensating forces and torques. The asymmetric prosthesis demonstrated in this research aims to find a balance between the different types of asymmetries to provide a gait that is more symmetric and to make it overall easier for an amputee to walk. Previous research has shown that a passive dynamic walker (PDW) with an altered knee location can exhibit a symmetric step length. An asymmetric prosthetic simulator was developed to emulate this PDW with an altered knee location. The prosthetic simulator designed for this research had adjustable knee settings simulating different knee locations. The prosthetic simulator was tested on able-bodied participants with no gait impairments. The kinetic and kinematic data was obtained using a VICON motion capture system and force plates. This research analyzed the kinematic and kinetic data with different knee locations (high, medium, and low) and normal walking. This data was analyzed to find the asymmetries in step length, step time, and ground reaction forces between the different knee settings and normal walking. The study showed that there is symmetry in step lengths for all the cases in overground walking. The knee at the lowest setting was the closest in emulating a normal symmetric step length. The swing times for overground walking showed that the healthy leg swings at almost the same rate in every trial and the leg with the prosthetic simulator can either be symmetric, like the healthy leg or has a higher swing time. Step lengths on the treadmill also showed a similar pattern, and step length of the low knee setting were the closest to the step length of normal walking. The swing times for treadmills did not show a significant trend. Kinetic data from the treadmill study showed that there was force symmetry between the low setting and normal walking cases. In conclusion these results show that a low knee setting in an asymmetric prosthesis may bring about spatial and temporal symmetry in amputee gait. This research is important to demonstrate that asymmetries in amputee gait can be mitigated using a prosthesis with a knee location dissimilar to that of the intact leg. Tradeoffs have to be made to achieve symmetric step length, swing times, or reaction forces. A comprehensive study with more subjects has to be conducted in-order to have a larger sample size to obtain statistically significant data. There is also opportunity to expand this research to observe a wider range of kinetic and kinematic data of the asymmetric prosthesis.

Disregard for patient-specific joint-level variability may be related to decreased functional ability, poor implant longevity and dissatisfaction post-TKA. The purpose of this study was to, 1) compare pre and post-implant intraoperative passive knee adduction angle kinematic patterns and characterize the effect of surgical intervention on each pattern, 2) examine the association between passive pre and post-implant knee kinematics measured intraoperatively and dynamic knee kinematics and kinetics pre and post-TKA measured during gait, and 3) compare dynamic post-TKA kinematic and kinetic patterns between patient-specific knee recipients and traditional TKA recipient. Patients received a TKA using the Stryker Precision Knee navigation system capturing pre/post-implant kinematics through a passive range of flexion. One-week prior and 1-year post-TKA patients underwent three-dimensional gait analysis. Knee joint waveforms were calculated according to the joint coordinate system. Principal component analysis (PCA) was applied to frontal plane gait angles, moments and navigation angles. Paired two- tailed t-tests were used to compare principal component (PC) scores between pre and post-implant patterns, and a one-way ANOVA was used to test if post-implant patterns were significantly different from zero. Two-tailed Pearson correlation coefficients tested for associations between navigation and gait PCscores, and an un-paired two-tailed t-test was used to compare PCscores between patient-specific and traditional TKA groups. Six different passive kinematic phenotypes were captured pre-implant. Although some waveform patterns persisted at small magnitudes post-implant (PC1 and PC3: p<0.001), curves remained within the clinically acceptable alignment range through passive motion. A positive correlation was found between navigation adduction angle PC1 and gait adduction moment PC1 pre and post-TKA (p<0.001, r=0.79; p<0.01 r=0.67), and a negative correlation between navigation adduction angle PC1 and gait adduction angle PC1 post-TKA (p=0.03, r=-0.53). The patient-specific group showed significantly lower PC2 scores than the traditional TKA group (p=0.03), describing a lower flexion moment magnitude during early stance phase, possibly representing a functional limitation or non- confidence during gait. These results were an important first step to assess patient- specific approaches to TKA, suggesting possible applications for patient-specific intraoperative kinematics to aid in surgical decision-making and influence functional outcomes.