Table 5. Categorical regression analyses with the eyes-closed Fourier Index 56 as a dependent variable and Q angle, Arch Index, Chippaux-Smirak Index, and foot position angle as independent variables. In other regression models with pillow under the feet and eyes-closed Fourier Index 56, head turned to the right and eyes-closed Fourier Index 56, and head turned to the left and eyes-closed Fourier Index 56 as dependent variables and Q angle, Arch Index, and Chippaux-Smirak Index independent variables.

	Eyes close - F56
	Standardized coefficients
Variable	Beta	Standard Error	F	p	R2
Q angle	0,453	0,106	18,185	<.001**
Arch Index	-0,159	0,098	2,626	0,110	0, 260
Chippaux-Smirak Index	0,027	0,102	0,070	0,792
Foot position angle	-0,079	0,095	0,685	0,411
	Pillow under the feet and eyes close-F56
Q angle	0,294	0,145	4,096	0.047*
Arch Index	-0,007	0,101	0,004	0,947	0,107
Chippaux-Smirak Index	0,023	0,112	0,044	0,835
Foot position angle	-0,047	0,095	0,243	0,623
	Head turned to the right and eyes close-F56
Q angle	0,297	0,135	4,857	0.031*
Arch Index	-0,030	0,103	0,088	0,768	0,106
Chippaux-Smirak Index	0,297	0,109	0,067	0,797
Foot position angle	-0,019	0,096	0,038	0,847
	Head turned to the left and eyes close-F56
Q angle	0,210	0,139	2,273	0,136
Arch Index	-0,022	0,118	0,033	0,856	0,138
Chippaux-Smirak Index	0,228	0,104	4,840	0.033*
Foot position angle	-0,101	0,109	0,853	0,136
* p<0.05; ** p<0.001.