The characterization of the kinematic and dynamic properties of the ankle joint for an artificial ankle joint design

Abstract

The kinematic and dynamic properties of the ankle joint (talocrural region) in normal subjects provide important information for the design of rehabilitation robots, below-knee prostheses, ankle-foot orthoses, and exoskeletons. This paper presents a quantitative analysis of published experimental data, simulation studies of human gait, and a dynamic model of ankle joint intrinsic and reflex stiffness to determine design requirements for such ankle devices to operate in the sagittal plane (i.e. ankle plantarflexion/dorsiflexion). The design requirements are derived in terms of average torque, rotatum, range of motion, velocity, acceleration, system bandwidth, torque-velocity curve, and the torque probability density function.