Figure 1.

Methods for the head impulse test and body impulse test. (A) Head Impulse Test. The examiner stood behind the subject and held the subject's head. Horizontal head impulses were manually applied to each side with unpredictable timing and direction by the examiner. (B) Body Impulse Test. Subjects were seated on a rotating stool, and wore a cervical collar to minimize neck movements. The examiner held both shoulders. Impulsive horizontal body rotation was manually applied to each side with unpredictable timing and direction by the examiner.