Relationship between head sway and center of foot pressure sway.

We investigated the correlation between body sway and head sway in 64 healthy subjects who stood on a force-measuring platform. Each subject wore a helmet attached to a cephalograph and was asked to stand as still as possible on a platform with his feet close together for 60 sec. Subjects were asked to do this three times with their eyes closed and three times with their eyes open. We selected the test with the minimum sway for computer analysis of the sway path, sway area, ratio of anteroposterior/lateral components, sway velocity in each direction, averaged divisional frequency, and Romberg quotient. The movement of the head was significantly correlated with the center of foot pressure (COF) for the sway path, sway area, sway velocity, averaged divisional frequency, and the Romberg quotient. Our findings suggest that COF sway can be used instead of head sway to assess those five parameters.