A limb (from the Old English lim), or extremity, is a jointed, or prehensile (as octopus arms or new world monkey tails), appendage of the human or other animal body.In the human body, the upper and lower limbs are commonly called the arms and the legs.Most animals use limbs for locomotion, such as walking, running, or climbing. Some animals can use their front limbs (or upper limbs in humans) to carry and manipulate objects.n the human body, the upper and lower limbs are commonly called the arms and the legs. Most animals use limbs for locomotion, such as walking, running, or climbing. Some animals can use their front limbs (or upper limbs in humans) to carry and manipulate objects.