“…A broad variety of procedures were used to measure the sagittal spinal curves. These were grouped into 6 categories as follows: plain x-ray films, 17,18,21,25,29,32,33,35,[37][38][39][40][41][43][44][45][46][47]49,51,53,55,57,59 distance measurement (apex of curve to surface), 14,20,23,30,34,62,67 and other specific-measure instruments 15,16,19,24,[26][27][28]42,50,56,58,63,64,66 (Table 2). In 6 studies, the sagittal curve of the cervical spine was evaluated 25,33,38,41...…”