The present application discloses a standing vertical lower limb exercise device. The lower limb exercise device includes two major pivotal members, a horizontal bridge member that connects the major pivotal members, a stretchable spring, a string member for limiting a split angle formed by the two major pivotal members, and wheels, gears, and shafts to facilitate movement of the two major pivotal members. The stretchable spring and string member are coupled between the two major pivotal members. Wheels are coupled to each major pivotal member.