| Types of measure |
Outcome measures |
Description |
Interpretation |
| Time-domain distance measures |
MDIST (mm)a |
Average distance from the mean COP |
Indicators of stability performance |
| RDIST (mm)a |
RMS distance |
| TOTEX (mm)a |
Total length of the COP path |
| RANGE (mm)a |
Maximum distance between any two points |
| MVELO (mm/s)a |
Average velocity of the COP |
Indicators of control demand |
| Time-domain area measures |
AREA-CC (mm2) |
95% confidence circle area |
Indicators of stability performance |
| AREA-CE (mm2) |
95% confidence ellipse area |
| Time-domain hybrid measures |
AREA-SW (mm2/s) |
Sway area |
Indicators of the relationship between control demand and stability performance |
| MFREQ (Hz)a |
Mean frequency |
| FD-RD |
Fractal dimension |
| FD-CC |
Fractal dimension based on the area-CC |
| FD-CE |
Fractal dimension based on the area-CE |
| Frequency domain measures |
T POWERa |
Total power frequency |
Indicators of postural regulations |
| 50% (Hz)a |
Median power frequency |
| 95% (Hz)a |
95% power frequency |
| CFREQ (Hz)a |
Centroidal frequency |
| FREQDa |
Frequency dispersion |
Indicators of trunk stiffness |