Table 2.

Pearson's correlation coefficients between the frame subtraction score and the GRF parameter

	DPSI	MLSI	APSI	VSI
Frontal plane
Maximum of the frame subtraction score	r = 0.747 P < 0.001	r = 0.464 P = 0.039	r = − 0.253 P = 0.282	r = 0.609 P  = 0.004
Sum of the frame subtraction score	r = 0.491 P= 0.028	r = 0.622 P = 0.003	r = − 0.069 P = 0.74	r = 0.527 P = 0.017
RMS of the frame subtraction score	r = 0.717 P  < 0.001	r = 0.592 P = 0.006	r = − 0.258 P = 0.272	r= 0.642 P = 0.002
Sagittal plane
Maximum of the frame subtraction score	r = 0.432 P = 0.057	r = − 0.020 P = 0.932	r = − 0.365 P = 0.114	r = 0.387 P = 0.092
Sum of the frame subtraction score	r = 0.306 P = 0.190	r = 0.265 P = 0.259	r = − 0.085 P = 0.722	r = − 0.301 P = 0.196
RMS of the frame subtraction score	r= 0.466 P = 0.039	r = 0.142 P = 0.551	r = − 0.278 P = 0.235	r = 0.419 P = 0.066
Combined planes
Maximum of the frame subtraction score	r = 0.566 P=   0.009	r = 0.106 P = 0.656	r = − 0.374 P = 0.104	r= 0.490 P = 0.028
Sum of the frame subtraction score	r = 0.405 P = 0.076	r = 0.426 P = 0.061	r = − 0.087 P = 0.716	r = 0.416 P = 0.068
RMS of the frame subtraction score	r =  0.606 P =  0.005	r = 0.305 P = 0.191	r = − 0.303 P = 0.194	r = 0.531 P  = 0.016

GRF ground reaction force, DPSI dynamic postural stability index, MLSI medial‒lateral stability index, APSI anterior‒posterior stability index, VSI vertical stability index, RMS root mean square

Only statistically significant variables (P < 0.05) are shown in bold