Date of download: 10/23/2017 Copyright © ASME. All rights reserved. From: A Low-Dimensional Sagittal-Plane Forward-Dynamic Model for Asymmetric Gait and Its Application to Study the Gait of Transtibial Prosthesis Users J Biomech Eng. 2009;131(3):031003-031003-9. doi:10.1115/1.3002757 Figure Legend: Illustration of the parsimony of human gait over a normal gait cycle. Average joint angles as a percentage of gait cycle for five adult subjects with normal gait using five trials each (bold). The dashed lines are the pointwise 1 standard deviation minimum and maximum joint angles. The normal gait cycle is composed of two symmetric steps, each comprised of a SS and a DS phase. Toe-off (TO) signals transition from DS to SS while HC signals transition from SS to DS. The subscripts “L” and “R” indicate the left and right legs as the stance leg. The superscripts “+” and “−” indicate the beginning and end of each phase. (Data courtesy of J. Linskell, Limb Fitting Centre, Dundee, Scotland .)

Date of download: 10/23/2017 Copyright © ASME. All rights reserved. From: A Low-Dimensional Sagittal-Plane Forward-Dynamic Model for Asymmetric Gait and Its Application to Study the Gait of Transtibial Prosthesis Users J Biomech Eng. 2009;131(3):031003-031003-9. doi:10.1115/1.3002757 Figure Legend: Coordinates for the minimal anthropomorphic model in SS and DS. Note the choice of coordinates as one absolute qa and the others relative. The relative coordinates specify the posture of the model, and the circles indicate the internal DOF. Note also the additional DOF at the trailing ankle in the DS model. The stance ankle-foot complex is modeled using the ROS . The ROS does not apply to the swing foot.

Date of download: 10/23/2017 Copyright © ASME. All rights reserved. From: A Low-Dimensional Sagittal-Plane Forward-Dynamic Model for Asymmetric Gait and Its Application to Study the Gait of Transtibial Prosthesis Users J Biomech Eng. 2009;131(3):031003-031003-9. doi:10.1115/1.3002757 Figure Legend: The joint torque costs for the hip (dashed) and knee (solid) of the prosthetic leg in swing, normalized by walking speed. The costs increase with increased mass and more distal location of the added mass.

Date of download: 10/23/2017 Copyright © ASME. All rights reserved. From: A Low-Dimensional Sagittal-Plane Forward-Dynamic Model for Asymmetric Gait and Its Application to Study the Gait of Transtibial Prosthesis Users J Biomech Eng. 2009;131(3):031003-031003-9. doi:10.1115/1.3002757 Figure Legend: The ROS is obtained by representing the center of pressure over a step in a shank-based coordinate system with the ankle as origin . The ROS is a model for the effective rocker the ankle-foot complex (physiologic or prosthetic) conforms to in the period between heel contact and opposite heel contact. In the physiologic case, the shape is well approximated by a circular arc and allows the stance foot motion to be modeled as rolling contact with the ground.

Date of download: 10/23/2017 Copyright © ASME. All rights reserved. From: A Low-Dimensional Sagittal-Plane Forward-Dynamic Model for Asymmetric Gait and Its Application to Study the Gait of Transtibial Prosthesis Users J Biomech Eng. 2009;131(3):031003-031003-9. doi:10.1115/1.3002757 Figure Legend: Steady-state walking speed with different radii of the prosthetic side ROS and different alignments. The different radii are expressed as a percentage of LL. For the larger radii, a step cannot be completed for the more anterior alignments.

Date of download: 10/23/2017 Copyright © ASME. All rights reserved. From: A Low-Dimensional Sagittal-Plane Forward-Dynamic Model for Asymmetric Gait and Its Application to Study the Gait of Transtibial Prosthesis Users J Biomech Eng. 2009;131(3):031003-031003-9. doi:10.1115/1.3002757 Figure Legend: Comparison of the step length of the prosthetic (dotted lines) or the sound leg (solid lines) with different radii of the prosthetic side ROS and different alignments. The different radii are expressed as a percentage of LL. For the larger radii, a step cannot be completed for the more anterior alignments.