Levels of sensorimotor representation

Problems of planning coordinated sensorimotor actions are examined within a cohesive framework based on seven levels of movement representation (conceptual, environmental spatial, effector, body spatial, joint motion, joint torque, and muscle) and the relationships existing among these levels. Emphasis is placed on discussions of the spatial motion, joint motion, and joint torque levels in the context of mathematical treatments of the degrees of freedom problem in motor control and the incorporation of environmentally supplied forces into movement planning procedures. Implications of this approach for understanding the nature of skilled actions are discussed, and applications of the mathematical treatments for simulation and experimental studies of coordinated movement are suggested.