Fig 4. The peak L/R spinal cord displacement averaged across all of the subjects and plotted as a function of R/C cord position (ie, vertebral level). The black line indicates the cross-subject average of peak displacement, whereas the gray area indicates the region within 1 SD of the mean at each R/C position. To facilitate comparisons between cord motions in each direction (A/P and L/R), the scale has been normalized to that shown for the larger A/P displacements (plotted in Fig 2). Note, however, that the average peak displacement is not significantly larger than 0.10 mm (the estimated measurement precision) at any R/C position, except at the level of T6.