Predicting the Biomechanics of Walking - Human Motion Simulation: Predictive Dynamics - page 181

location is optimized to facilitate an energy-saving walk for different backpacks
to increase stability and reduce the joint torques. Thus, the current algorithm pre-
dicts that people will choose a strategy to walk more efficiently for carrying back-
packs under the given walking parameters.
7.13 Implementations of the predictive dynamics walking
formulation
7.13.1 Effect of constrained joints
Constrained joints refer to the range of motion limitations in various joints that
can be due to disabilities, injuries, or physical restraints. Examples of physical
restraints include clothing of various thickness and stiffness, and rigid objects that
can be worn by humans such as knee pads and armor material. The predictive
dynamics formulation for walking takes into consideration ranges of motion as
limitations on the DOF for each joint. These are imposed as inequality constraints
that can be varied at any time.
7.13.2 Sideways and backward walking
Sideways and backward walking are important aspects of walking simulation and
are indeed a realistic human behavior.
7.13.3 Effect of changing anthropometry
Because of the implementation of the DH parameters, the dimensions of each
body part are readily implemented into the DH table. Therefore, a simulation can
include variations in anthropometric measures to see the effect on the motion.
Note that any change in anthropometry should be, although not necessarily,
accompanied with a change in the set of strength surfaces associated with that
simulation. Limits of strength are assigned as presented in Chapter 6.
7.13.4 Effect of changing loads
As demonstrated in the previous section, a change of loading on the human will
directly affect the optimization problem. Loads on the arms, legs, torso, or any
other body location can be simulated and their effects calculated and visualized.
Loading effects are of particular importance for athletes, military personnel, and
workers in industrial settings. Analyzing and better understanding the effect of
loading on human performance is at the core of predictive dynamics and is why
this topic was created.