Static Subjective Visual Vertical in Healthy Volunteers: The Effects of Different Preset Angle Deviations and Test-Retest Variability.

The static subjective visual vertical (SVV) was assessed in 24 healthy volunteers with different preset angles (i.e., 10, 20, and 30 degrees), and in 20 other volunteers, the static SVV was tested and retested 1 week later. The static SVV results are influenced by the side of the preset angle (Wilcoxon test, p ≤ 0.001), but not by the preset angle deviation. The test-retest static SVV outcomes are stable at a group level; however, they show statistically relevant variability at an individual level (-0.240 ≤ intraclass correlation coefficient [ICC] ≤ 0.508). A robust static SVV protocol is described in this paper.