ABSTRACT

Complex motor tasks such as human or animal locomotion require a concerted action of body mechanics, muscle dynamics, and sensor function. For successful movements a careful com - bination of fast mechanical pre-fl exes (Brown & Loeb, 2000) with feedforward and feedback control is required (Dickinson et al., 2000). Surprisingly, during fast and dynamic legged movements like running or hopping, the body function resembles simple movement templates (Full & Koditscheck, 1999), which can be characterized as an overall spring-like response of the body during ground contact. This unifying behavior can be found in human and animal locomotion and has motivated a class of simple gait models based on the spring-mass model (Blickhan 1989; McMahon & Cheng, 1990), also called the spring-loaded-inverted-pendulum (SLIP) model (Schwind, 1998).