The Study: Validity of palpation of the C1 transverse process: comparison with a radiographic reference standard
- The authors wished to determine if it was possible to accurately locate the transverse of atlas by the use of palpation.
- They placed markers at the transverse of atlas on 21 subjects.
- The placement of the markers was determined by the use of palpation.
- Radiographs were taken and the accuracy of the placement of the markers compared to the transverse process of the atlases as seen on the radiographs was noted.
- The authors felt that it was not easy to place the markers as you had to remove your finger in order to make the placement and this may have affected accuracy. Also the patient's head may have tilted between the placement and the radiograph and that may have affected accuracy.
- The center of the transverse process as determined by radiograph was within + or - 4mm of the center of the markers placed by palpation in 57.1% of the cases.
Although there may have been some problem with placement of the marker it appears that an accuracy of locating the transverse of atlas within 4mm. can be done over half the time.
Remember the line. "It depends on what the meaning of is, is." Well it depends on what you think accurate is. I always love people who say well you are off by X (put in some small value) therefore your idea is no good. On the other hand some people say that it's only off a little bit (put in a much larger value) so it's OK. If you are measuring a football field then 4mm is really great. If you are measuring the distance between electrons, then not so much.
In practical terms, I look at it in this manner. How big is the area that you are using to contact the transverse of atlas when you adjust? I've got a feeling that you'll find it's a lot bigger than 4mm. I've spent a large part of my life thinking about measurements on x-rays and I really like studies such as this one, but I always try to remember that there is a practical aspect to all of these measurements. So I leave it up to you as to how close you really need to be.
Reviewer: Roger Coleman DC
Editor's Comments: I had a personal interest in this paper, as I did essentially the same project as my senior research paper at Life College. As I recall we had only about 15-16 participants, all student clinicians, who were asked to palpate and mark the C-1 transverse process on their patients during the initial examination. Unfortunately, our results were not nearly so positive, with the average doctor palpating at about C2-3 instead of over Atlas. This study used two examiners with much more experienced (one with eight years and the other with two years of experience) and that experience appears to have played a tremendous role in terms of accuracy. Encouraging!
Editor: Mark R. Payne DC
Reference: Cooperstein R, Young M, Lew.Validity of palpation of the C1 transverse process: comparison with a radiographic reference standard. J Can Chiropr Assoc. 2015 Jun;59(2):91-100.
Link to Abstract: http://www.ncbi.nlm.nih.gov/