Analysis of motor-knee joint misalignment during walk, jog and squat activities with a lower-limb exoskeleton
University of New Brunswick
Lower limb exoskeletons are electromechanical devices that assist the user by transmitting motor torques to the user's musculoskeletal system. Biomechanical effectiveness depends on alignment between exoskeleton joints and joints of the user. The objective of this thesis was to quantify joint misalignment between an exoskeleton and user to determine what factors contribute to misalignment and if it impacts the performance of the user. An existing 3D motion data set of healthy users performing walk, job and squat activities with and without wearing a lower-limb exoskeleton was analyzed to quantify the motor-knee joint centre translational offset. Correlation analysis was performed between the offset and motor torque, knee angle, height, weight, and gait speed. Offset correlation with knee angle and motor torque varied depending on the loading condition. The offset was not correlated with the difference in gait speed with and without the device. The results demonstrate that joint misalignment is present and varied depending on the loading condition of the leg.