knee-jerk reaction. Fig. an automatic or reflex reaction; an immediate reaction made without examining causes or facts. With one of his typical knee-jerk reactions, he said no immediately, citing some moral argument that no one understood. See also: reaction.
What did you see when the patients head was rolled to the opposite side? In horizontal canal BPPV, you should have seen a direction change. When the horizontal nystagmus is geotropic, the BPPV is suspected to be canalithiasis, occurring on the side with the more intense nystagmus.
Best Answer: Horizontal and vertical are simply directions relative to some reference frame. Typically the reference frame in HS and early college physics is Earth's surface.In which case horizontal means parallel to Earth's surface and vertical means perpendicular to Earth's surface.In advanced math and physics, the terms horizontal and vertical will be replaced by unit vectors i, j, and k; where i dot i = 1 etc.nd Ay = A, which means the A vector is pointing straight up the vertical axis. In this case, there is no Ax component. In higher trig you will learn about transformations where we rotate the axes some degrees with the result sometimes of simplifying an otherwise difficult problem.