Center of Pressure parameters during quiet standing.

Mean (± SEM) center of pressure parameters from the quiet standing posture during four sensory condition: eyes open and firm surface (EO), eyes closed and firm surface (EC), eyes open and soft surface (EO-soft) and eyes closed and soft surface (EC-soft). The CoP Standard Deviation (SD) and speed in medial–lateral (ML) and anterior–posterior (AP) directions are presented for the less severe (KL score 1 and 2), severe (KL score >2) groups. Significant increases in body sway during EC-soft compared with EO-soft condition are indicated (*, interaction between surface and vision; NK: P0.01). Significant increase in body sway during EC compare EO condition is marked with “#” (interaction between surface and vision; NK: P = 0.02). Significant higher values during EC-soft compared with all other conditions (¥, Interaction between surface and vision; NK: P