Abstract: A self-actuated spring-action human bipedal device includes a back-mounted frame attached to the upper torso of a user, and separate articulated right and left leg frames pivotally attached by U-joints to lower portions of the back frame. The user's feet are secured to the leg frames so the bottoms of the leg frames contact the ground, behind and below the point where each foot is attached to its leg frame. Endless cord-like main springs are engaged with a spring actuator, which are carried on the back frame. Left and right tension lines running from respective leg frames to the spring actuator are arranged so that compression of the leg frames, caused by the force of downward movement of the user's feet and torso, pulls on the tension lines to apply a pulling force to the spring actuator for stretching the main springs.