LifeMOD 2007
The LifeMOD/BodySIM Biomechanics Modeler is a plug-in module to the ADAMS physics engine. The creation of human models begins by generating a base human segment set, followed by joints, soft tissues and contact elements between the model and the environment. Any given simulation runs from a specific starting posture. The models created in LifeMOD/BodySIM may be passive or active. Passive models are reactive to the environment around them. Most tests run like the physical tests performed on crash dummies, measuring the body’s reaction to outside stimuli. Since the body itself does not cause or drive any of the motion, motion agents and programmed muscle functions are not necessary. Active models cause reactions in the environment. In order to achieve accurate simulations of muscle and joint movement, an inverse-dynamics simulation is run first to record angulations and muscle-contraction histories for the target body segments. Motion agents are positioned on the model to drive the movement and “teach” the joints and soft tissues how to move. Once the necessary movements have been recorded in an inverse-dynamics simulation, the compiled movement histories are then ready to drive the forward dynamics simulations, which test the subject in an applicable environment.
Figure: LifeMod model showing the floor, muscles, marker positions from motion analysis and force vectors from the contact between the ground and the foot