objectives: this paper describes further improvement and preliminarily evaluation of a novel viscoelastic ankle-foot prosthesis prototype. the objective was to control the ankle hysteresis at slow and normal walking speeds. methods: inspired by the ankle biomechanics, in which the hysteresis differs based on the gait speeds, a manually damping control mechanism imbedded in the prosthesis for ad...

The first step to study and develop a two Degrees of Freedom (DOF) prosthesis is to derive a dynamic model for simulation and control design. In this paper, the ankle-foot prosthesis has controllable Dorsi-Plantarflexion (DP) and Inversion-Eversion (IE) DOF. We derive a compliant dynamic model for a recently developed ankle-foot prosthesis followed by identification of the actuators, transmissi...

A load deflection and a cyclic loading apparatus capable of measuring dorsiflexion/plantarflexion, pronation/supination, internal/external rotation, and cyclic dorsiflexion (60 cycles per minute) of ankle-foot prostheses are described. A test protocol was developed to assess the functional parameters of the Jaipur ankle-foot prosthesis before and after prolonged cyclic loading, with the simulta...

The gait patterns of unilateral below-knee amputees wearing prostheses with either a SACH foot or a single axis foot were compared. A temporary below-knee prosthesis was fabricated for each subject using plaster of Paris and Plastazote for the socket, a pylon and an artificial foot. Eight subjects were filmed at two separate sessions, one in which the SACH foot was worn on their prosthesis and ...

Objectives: This paper describes further improvement and preliminarily evaluation of a novel viscoelastic ankle-foot prosthesis prototype. The objective was to control the ankle hysteresis at slow and normal walking speeds. Methods: Inspired by the ankle biomechanics, in which the hysteresis differs based on the gait speeds, a manually damping control mechanism imbedded in the prosthesis for...

In this work, we present a model for human leg with prosthetic foot, consisting of rigid bodies the thigh and shank geometrically exact beam prosthesis. The prosthesis is modelled after Össur Vari-Flex® carbon spring foot. individual are connected by joints imposing constraints, mimicking motions joints. A structure preserving variational integrator used to calculate forward dynamic simulation ...

In recent years, numerous prosthetic ankle-foot devices have been developed to address the demands of sloped walking for individuals with lower-limb amputation. The goal of this study was to compare the performance of a passive, hydraulic ankle-foot prosthesis to two related, non-hydraulic ankles based on their ability to minimize the socket reaction moments of individuals with transtibial ampu...

Investigations into the gait of persons with partial foot amputation (PFA) suggest that the effective foot length can be restored when the prosthesis incorporates a relatively stiff forefoot, restricts dorsiflexion, and includes a mechanism whereby forces caused by loading the toe lever can be comfortably distributed to the leg (e.g., an anterior tibial shell). The purpose of this investigation...

the need for simulation of human foot mechanism has made researchers and engineers move towards different patterns to describe this movement. in this regard, optimal solutions such as energy consumption, accuracy, etc. are of utmost importance. in this paper, efforts have been made to present a new solution by designing a fully two-dimensional six-bar mechanism with one degree of freedom so tha...