Figure 3

Photograph of the (A) experimental setup for measuring intervertebral displacement and (B) flexion motion of intact lumbar spine. By using a specially designed fixture, an 8,400 N-mm constant moment generated through the axial movement of the MTS actuator was applied to the spine specimen to achieve flexion and extension motions. Intervertebral displacement at L4–L5 adjacent to the fusion level was recorded continuously using an MTS extensometer.