Final answer:
The term to describe shifting the body from one leg to the other while moving forward or back is stepping. This involves the stance leg supporting the body while the step leg moves forward.
Step-by-step explanation:
The term used to describe shifting the body from one leg to the other while moving forward or back is stepping. During normal walking, bipedal organisms balance their body weight on one leg, known as the stance leg, while the other leg, the step leg, is off the ground and moving forward.
At any given time during walking, both feet are on the ground for about 25% of the time. As walking speed increases, the duration when both feet are on the ground tends to decrease. This stepping motion allows for the propulsion needed to continue moving.