Which COP metric describes the total area swept by the center of pressure during a balance task?

• A. Path length
• B. Sway area
• C. Mean velocity
• D. Latency

Answer: (B)

The main idea here is how we quantify how much the center of pressure covers the surface during standing. The total area swept by the CoP trajectory is described by sway area. As you sway, the CoP traces a path on the support surface; the sway area captures how wide that path expands in two dimensions, often summarized by the area of a 95% confidence ellipse around the trajectory. This differs from path length, which sums all movement distance along the path, or mean velocity, which is speed averaged over time, while latency relates to timing of a response to a perturbation rather than the extent of sway. So sway area best reflects the overall spatial footprint of postural sway.