FIGURE 1.

Study overview. (A) Experimental setup. Upper panel: subject standing on the force plate in the feet-apart condition. Lower panel: body sway output. The body sway amplitude is the displacement of the center of gravity in the anteroposterior (y-axis) or mediolateral (x-axis) direction, the sway path is the distance traveled by the blue line. (B) Differences in body sway amplitude between patients and controls (left) and asymptomatic patients and an age-matched selection of controls (right). (C) Two examples of the association between clinical severity of myelopathy and body sway: EDSS and total sway amplitude (left) and 6MWT and total sway amplitude (right). The lines represent simple linear regression lines.