Can skin markers represent spinous process when the posture is changed?

Abstract

The objective was to radiographically verify if the position of skin markers, identified by palpation in orthostasis posture, changes when the subject position shifts to lying posture. Ten subjects underwent two X-ray tests, first, in orthostasis and right lying posture. Ten subjects were palpated and marked with skin markers in the orthostasis posture, in the spinous process of the vertebrae C7, T2, T4, T6, T8, T10, T12, L2, L4 and S2 . After palpation, subjects underwent X-ray exams in orthostasis and lying postures to verify if the surface marker matched the spinous process shown on X-ray. A two-way ANOVA indicated significant differences for the displacement of the skin markers, for the C7, T2, T4, T6, T8, T10, L2 and S2 spinous processes (p<0.001). The T12 and L4 spinous processes did not indicate significant differences. The skin markers locations were not consistent with the spinous processes identified in X-rays for both positions. The skin movement may have displaced the skin markers when the subject changed from orthostasis to lying posture.