Abstract
After investigating muscle structures and their functions in insect legs, a four-legged mechanical model that completely describes any kinds of leg motion and structure is developed. Dynamic equations of motion, inverse kinematics, foot trajectory equations, and reaction forces are derived. To design a computationally efficient leg mechanism, a computer program called WALK is developed and used to compute the mechanical efficiency, depending on several factors such as duty factor, velocity, and divided front and rear stroke variations.