| BACKGROUND: Palpation is a fundamental part of chiropractic practice, commonly used to identify specific vertebral levels in the spine. The top of the iliac crests is a landmark generally used to locate the spinous process of L4 or the interspinous space of L4/L5. While palpation is widely used, studies have shown only minimal concordance and it has been suggested that misidentification of the exact segmental level may be a primary source of inter-examiner error in reliability studies on motion palpation. OBJECTIVE: The purpose of this study is to document the radiographic variability of the intercrestal line to the lumbar spine in order to evaluate its use as a reliable landmark. METHODS: Four-hundred and one (401) full spine (14 x 36) anterior to posterior (A-P) and lateral radiographs were reviewed following a prospective approval by Life University’s IRB committee. The iliac crests were identified on the A-P radiograph and marked with a line drawn across the film connecting the right and left crest at the superior most margins (intercrestal line). Other findings recorded including the presence of sacralization, lumbarization, spondylolisthesis, or scoliosis in the lumbar spine. RESULTS: In this study, 46.6% of our population sample was found to have L4 spinous process on the intercrestal line, while in 21.7% the interspinous space of L4/L5 was located between the crests. Analysis by gender showed that 66.5% of males had L4 identified on the intercrestal line while only 32.9% of females did. We found that although 30.3% of our subjects had an observable lumbar scoliosis, only 2% had a Cobb angle over 10 degrees. Spondylolisthesis was found in 5.7% of our subjects with twice the occurrence in females (69.6%) over males (30.4%). The majority of subjects (90.3%) had 5 lumbar vertebrae, while 3.2% had only 4 lumbar vertebrae and 6.5% had 6 vertebrae. DISCUSSION: In our study, almost one third of the subjects had some structure other than L4 or the interspinous space of L4/L5 identified on the intercrestal line. This demonstrates that the chiropractor cannot reliably identify a particular lumbar segment by palpation using the point between the iliac crests alone. CONCLUSION: The intercrestal line is not a reliable or specific landmark for identifying the spinous process of L4 or the interspinous space of L4/L5. This abstract is reproduced with the permission of the publisher. |
