commonly available type which can be easily obtained commercially the landing shock of a rear toe 80 is transmitted to the shock absorber 50 and is absorbed thereby here since the vertical axis of the rear toe 80 of the foot system is always parallel with the vertical axis of the shock absorber 50 in cooperation with the parallelogram configuration of the upper and lower parallel links 100 101 and 110 111 the contact trajectory is positioned on a symmetrical line with the shock absorber axis therefore since the shock absorber is applied with only the force in the symmetrical axis direction it is possible to achieve a desired performance of the shock absorber 50 the piston rod of the shock absorber 50 is fully compressed by the body weight after landing as the foot system rotates in the pitch direction of the shank 230 after landing the piston rod of the shock absorber extends by the force of an internal spring not shown whose reaction force is very small with reference to fig7 a through 7e the operation of the foot system for a jointed leg type walking robot will now be explained in more detail fig7 a shows a landing phase of the robot as shown therein when the foot system lands on the ground surface the rear toe 80 lands thereon earlier than the front toe 70 the shock absorber 50 is compressed by the force which occurs when the.