Symptom localization tests in the cervical spine: a descriptive study using imaging verification.

The concept of isolation of a movement to a single specific spinal segment by blocking/stabilization is considered useful and important during both examination and treatment. This descriptive study endeavoured to determine whether a typical manual stabilizing procedure changes movement patterns in the cervical spine. Lateral radiographs were taken of five volunteers in active/assisted extension with and without manual fixation grasping with the thumb and fingers around the dorsal aspect of the neck at the level of the vertebral arch. Vertebral angular differences between the fixated and non-fixated movements were measured for intra-rater and inter-rater reliability using an intraclass correlation coefficient (ICC) and analyzed for differences using a student t-test. Intraclass correlation coefficient values for intra-rater reliability were fair to moderate whereas inter-rater reliability was excellent. Although not statistically significant, the results showed that in relation to the active extension, the vertebra above the fixated vertebrae moved slightly less (mean = -0.08°; SD = 2.55) as did the vertebrae two levels above fixation (mean = -0.11°; SD = 2.13). Movements of the vertebrae below the fixation and two levels below the fixation were also reduced (mean = -1.09°; SD = 2.07) and (mean = -0.65°; SD = 1.85) respectively. The results suggest the possibility of a three-point bending of the spinal column during fixation and symptom localization during fixation may be a product of soft tissue tension and/or pressure from the fixating fingers. Further research is necessary, including a design that allows consistency among all participants which is appropriately powered.