(a) component x
  a b  c R2
Romberg's posture 1.01 -0.21 -5.71 0.98
Posture I 1.37 -0.15 -5.74 0.97
Posture II 1.25 -0.06 -5.42 0.85
(b) component y
  a b  c R2
Romberg's posture 0.81 -0.02 -5.57 0.83
Posture I 1.04 -0.25 -5.73 0.98
Posture II 1.56 -0.36 -5.87 0.99
Table 1: Coefficients of the potential function in each component: (a) lateral direction x, and (b) anterior/posterior direction, while subject’s eyes were open.