Fig. 1From: Mobile phone app Vs bucket test as a subjective visual vertical test: a validation studyOn the exterior base of the bucket, a plumb line originating from the center projected over an 1800 protractor, which is aligned with the straight diametric line on the inside base of the bucket. The iPod Touch with Visual Vertical was secured such that it was aligned with the zero- line of the degree scaleBack to article page