Lumbar vertebral columns, removed from 23 male cadavers aged from 18 to 84 years, were tested for their reaction to a longitudinal traction load. Sustained lumbar traction using a load of 9 kg for 30 min was applied to each specimen. The amount of initial distraction and traction creep recorded. Initial vertebral separation was greatest in those specimens with wide disc spaces and least where there was evidence of disc degeneration. The residual deformation on load removal was slower and less complete in the older subjects.