The Core Lumbar Strength F3 is the only mid-back exercise machine that uses the patented and effective fixation mechanism for the pelvis. This is the only way to eliminate all auxiliary muscles that work synergistically from the movement chain and tackle the deep-seated back muscles in isolation. This machine combines elements that enable you to perform a low-weight, muscle-strengthening exercise program with the back supported by a split seat. The setting of the fixation elements (foot plate, knee, and shin pads) can be adjusted from the sitting position to body size and bending angle of the legs and controlled via a scale.