Table 1 shows the work done by the joint actuators and the foot actuator. The work is normalized by the distance traveled during one step. The normalized work done by the robot with foot actuation is less than the robot without foot actuation, which implies that having foot actuation
helps to reduce the work required to walk

Table 2 shows other parameters to calculate the Poincaré return map and the fixed point.

• Junho Choi and J.W. Grizzle, "Feedback Control of an Underactuated Planar Bipedal Robot with Impulsive Foot Action", Pre-print, paper submitted to Robotica. Paper submitted June 2, 2004.