Quantifying Kinematic Adaptations of Gait During Walking on Terrains of Varying Surface Compliance

Locomotion is essential for a person's ability to function in society. When an individual has a condition that limits locomotion, such as a lower limb amputation, the performance of a prosthetic often determines the quality of life an individual regains. In recent years, powered prosthetic devices have shown nearly identical replication for human leg motion on non-compliant terrains. However, they still face numerous functional deficits such as increased metabolic cost and instability for walking on surfaces of varying compliance and complexity. This paper proposes joint angles of the biological leg are uniquely altered by surface compliance regardless of a subject's individual walking pattern. These differences are then displayed and quantified as a way to better characterize able-bodied walking compensation typical with three common terrains: sand, grass and gravel. This study also collects data outdoors using IMU sensors and is not limited by lab setup and conditions. These results are important since better understanding of joint angle kinematics on varying terrains could enable the formulation of advanced controllers for current prosthetic devices allowing them to anticipate surface changes and adapt accordingly.