How models help us to understand the interactions between posture and voluntary movements

Summary form only given. Modeling and computer simulation studies of the human motor control system, which provide a valuable method to both neuroscientists and robotics engineers interested in a control systems approach to the study of coordinated movements, are described. A single-joint, neurological control model for simulation studies of human movements is presented. This model consists of an idealized pair of muscles acting antagonistically to move a common load. Each muscle is described by three components: a first-order large element, which relates the neurological control signal to a hypothetical muscle tension; a nonlinear series elasticity obeying the length tension property of skeletal muscle; and a nonlinear apparent viscosity obeying the force-velocity relationship. The load is a linear, second-order system. This basic model has been used to explore the relationships between electromyographic recordings and observed movement kinematics in movements of the eye, ankle, and wrist. It is shown that, with this model, a multitude of hypotheses regarding the integrated motor control strategies for both voluntary movements and postural control can be examined.<>