Prospective analysis of sagittal vertical axis
(SVA) on lateral spine radiographs using 3 different arm positions.
To examine whether fists-on-clavicles position represents a functional standing position.
Summary of Background Data.
Radiographic visualization of spinal and pelvic sagittal morphology is difficult during relaxed standing because of interference from the arms; however, standing with arms forward-flexed results in a negative shift in SVA. The fists-on-clavicles position was proposed to provide a more functional sagittal profile and adequate visualization of the spine. No existing study compares the SVA between the fists-on-clavicle and relaxed standing positions.
The SVA was measured on standing lateral radiographs of 14 healthy subjects using 3 different arm positions: relaxed with arms-at-side, arms forward-flexed to 45° (shoulder flexion [SF]), and fists-on-clavicles.
The mean SVA with relaxed standing was 1.4 ± 1.9 cm. SF produced a significant SVA negative shift (−3.7 ± 2.3 cm, P
< 0.001). The fists-on-clavicle position resulted in a reduced but significant SVA negative shift (−2.3 ± 2.1 cm, P
< 0.001) compared with relaxed standing.
Although the fists-on-clavicles position was better than SF in reducing the SVA negative shift, a significant negative shift did occur in the fists-on-clavicle position compared with relaxed standing.