The Lovett Reactor refers to the relationship between vertebral motions in which the atlas and 5th lumbar vertebrae rotate in the same direction during gait cycle. This relationship continues through the entire spine, with C2 rotating in the same direction as L4 and C3 with L3. At this point, the movement shifts to counter-rotation as C4 counter-rotates with and C5 with L1. The counter-rotation continues throughout the rest of the spine until the upper half of the spinal column meets the lower half at the 5th and 6th thoracic vertebrae.
