Validity of palpation techniques for the identification of the spinous process L5

For spinal diagnosis and treatment it is important to be able to identify spinal levels by palpation. The objective of this diagnostic study was to examine the validity of four palpation techniques to detect the fifth lumbar vertebra (L5). A physiotherapist examined 66 low back pain patients using first three techniques. Motion palpation (MP), palpation via the posterior superior iliac spines (PSIS technique) and palpation via the iliac crests (CI technique) were deployed in random order. The spinous processes identified using these techniques were marked using an UV marker. The fourth technique was the motion palpation using the previously visible marked landmarks PSIS and CI (MP+). X-rays were taken as a reference standard through replacing the markings by radio-opaque markers. The accuracy of the single techniques ranged from 45% to 61%. There was no significant difference between the individual techniques. If two techniques were in agreement the accuracy ranged from 58% to 78%. If three techniques were in agreement the accuracy ranged from 69% to 83%. This was a significant to highly significant improvement compared to single techniques. If there is agreement between palpation techniques, the accuracy can be significantly improved. This illustrates the need to combine techniques and to relate them to each other. Future studies should investigate combined techniques using marker for further anatomical structures.