Table 4:

Measures of Foot Structure, Flexibility, and Function for Total Sample and Comparisons of Measures across 3 foot types.

Variable	All (N=2,180)		Planus (N=1,601 feet; 73.4%)		Rectus (N=443 feet; 20.3%)		Cavus (N=113 feet; 6.2%)		X2	P-Value	Post hoc
(unit)	Mean	SE	Mean	SE	Mean	SE	Mean	SE			P v R	P v C	R v C
AHI, sitting	0.369	0.001	0.342	0.001	0.370	0.001	0.394	0.002	1113.32	0.000	0.000	0.000	0.000
AHI, standing	0.347	0.001	0.317	0.001	0.349	0.001	0.375	0.001	2409.050	0.000	0.000	0.000	0.000
Arch Drop (cm)	0.41	0.01	0.48	0.01	0.41	0.01	0.36	0.21	54.12	0.000	0.000	0.000	0.017
ΔFL (cm)	0.41	0.01	0.37	0.01	0.41	0.01	0.45	0.03	17.93	0.000	0.000	0.001	0.117
AHF (mm/kn)	14.27	0.29	16.47	0.23	13.97	0.37	12.38	0.66	55.05	0.000	0.000	0.000	0.019
MVI (%)	9.66	0.24	11.10	0.18	9.74	0.34	8.13	0.61	31.89	0.000	0.000	0.000	0.021
CPEI (%)	22.74	0.23	21.59	0.19	22.78	0.31	23.86	0.51	23.68	0.000	0.000	0.000	0.051
PP (N/cm2)	57.99	0.60	59.13	0.53	57.38	0.77	57.47	1.19	4.96	0.084

Feet are categorized into planus, rectus, and cavus foot types based on mean standing AHI obtained from previous study [21]. Planus foot type showed significantly lowered standing AHI and greater MVI (pronatory foot posture), greater AHF, and smaller CPEI than rectus and cavus foot types. Significant difference was observed between rectus and cavus foot types, all except foot elongation and CPEI. Given significantly greater arch drop, commensurate foot elongation was expected in planus foot type. Surprisingly, planus feet demonstrated a significantly reduced foot elongation than rectus and cavus foot types.