Association between cervical and thoracic somatic dysfunction among second-year osteopathic medical students

Context: The ubiquitous nature of cervical and thoracic somatic dysfunction requires osteopathic physicians to have a strong working knowledge of regional spinal mechanics and their functional and dysfunctional interrelationships.

Objective: To determine whether cervical and thoracic somatic dysfunction occur concomitantly, particularly somatic dysfunction of the occipitoatlantal (OA) and upper thoracic (T1-T4) region of the spine.

Methods: A retrospective analysis of cervical and thoracic somatic dysfunction prevalence diagnosed by faculty in second-year osteopathic medical students was conducted. Somatic dysfunction was defined as a vertebral unit possessing any of the following palpatory characteristics: tissue texture changes, asymmetry of motion and relative position, restriction of motion, or tenderness (ie, TART criteria). For each instance of somatic dysfunction diagnosed, the segmental level identifying the superior segment of the involved vertebral unit was recorded, as well as the spinal region (ie, cervical [OA, atlantoaxial (AA), and C2-C7] or thoracic [T1-T12]). Descriptive analyses, a Pearson χ(2) test, and a regression model using an analysis of variance were performed on the data.

Results: Among 338 students included in the study, the following 5 vertebral segments were found to have the highest prevalence of somatic dysfunction: OA (257 [76.0%]), C3 (257 [76.0%]), T3 (247 [73.1%]), T5 (226 [66.9%]), and T4 (223 [66.0%]). A Pearson χ(2) test of association between the OA vertebral segment and the following segments were found to be statistically significant: AA (P=.024), C2 (P=.032), and T4 (P=.045). An analysis of variance revealed statistical significance between the prevalence of upper cervical (OA, AA, C2) somatic dysfunction and the prevalence of upper thoracic (P<.001) and midthoracic (T5-T8) (P<.001) somatic dysfunction; the prevalence of lower cervical (C3-C7) (P=.74) and lower thoracic (T9-T12) (P=.085) somatic dysfunction was not found to be significant.

Conclusion: A statistically significant association between cervical somatic dysfunction and thoracic somatic dysfunction was confirmed. In addition, there was a statistically significant association between dysfunction of the OA and the AA, C2, and T4 vertebral segments. These results suggest that the number of dysfunctional vertebral segments in the upper thoracic and midthoracic spinal regions is directly proportional to the number of dysfunctional segments found in the upper cervical spinal region.