AbstractA crucial point in developing walking machines is the load to weight ratio. Leg design and in it the drives essentially determine the leg's weight. Therefore it makes sense to optimize the design as well as the best motor‐gear‐combination with respect to power density. Some typical principles of legs have been derived from biological findings, especially for insects. The technical solution was adapted to these principles in an optimal way. The resulting leg achieves a load to weight ratio of approximately six. © 1995 John Wiley & Sons, Inc.