ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

Table 1: Models used in this study.
Model Gait Subject Knee Body Level
Prosthetic Female, age unknown, Instrumented prosthetic left knee Upper and
height 167 cm, weight 78 kg
lower
Natural Female, age 27, height 175 Cadaver left knee, female, age 55, Lower only
cm, weight 64 kg
height 170 cm, weight 73 kg
The force magnitude of each muscle actuator was determined by feedback
controllers using the error signal between the current muscle length and the muscle
length recorded during the inverse dynamics simulation (target length). The force of
each muscle during the forward dynamics simulation was calculated from a
proportional–integral–derivative feedback controller (PID). The PID control algorithm
used the recorded muscle contraction as a target to generate the muscle force with the
following functions: