Figure 2.
X-ray lumbosacral spine lateral view showing (a) Measurement of instability according to posner;3 Dynamic lateral film (flexion) in standing posture showing >10° sagittal rotation (angular displacement); measurement is done by the angle formed between the two adjacent end-plates. (b) Dynamic film in extension. (c) The dynamic films producing anterior translation measured as the distance between a and b= d (in flexion). (d) The distance of a1 and b1 = d1 (in extension). The distance difference (D) in flexion (d) and extension (d1) calculated as the percentage (D = d – d1 above vertebral width ×100) of the width of the above vertebra