Table 6.

The duration of retrograde flow (RT) in the great saphenous vein (GSV) of lower limbs (n = 60 each) in children with myelomeningocele (MMC group) and typical developing children (TD group) in the horizontal position and vertical position.

Group	GSV segment	RT (s) Horizontal position			RT (s) Vertical position			Statistical tests P-values
		Mean (sd)	Median	Range	Mean (SD)	Median	Range
MMC	P1	0.22 (0.08)	0.20	0.00–0.70	0.29 (0.11)	0.27	0.00–0.50	U = 3.25; P = 0.004
	P2	0.18 (0.08)	0.16	0.00–0.50	0.27 (0.21)	0.25	0.00–0.50	U = 3.76; P = 0.001
	P3	0.27 (0.06)	0.25	0.00–0.50	0.46 (0.16)	0.44	0.00–1.00	U = 2.81; P = 0.005
	P4	0.24 (0.11)	0.22	0.00–0.50	0.36 (0.16)	0.32	0.00–1.50	U = 2.92; P = 0.001
TD	P1	0.04 (0.04)	0.00	0.00–0.12	0.05 (0.05)	0.03	0.00–0.10	U = 1.31; P = 0.565
	P2	0.06 (0.04)	0.00	0.00–0.12	0.06 (0.04)	0.00	0.00–0.10	U = 1.29; P = 0.589
	P3	0.06 (0.04)	0.00	0.00–0.13	0.09 (0.04)	0.00	0.00–0.30	U = 1.27; P = 0.608
	P4	0.08 (0.05)	0.00	0.00–0.12	0.11 (0.04)	0.00	0.00–0.20	U = 1.52; P = 0.543

GSV, Great saphenous vein; P1, proximal thigh level; P2, medial thigh level; P3, upper leg level; P4, lower leg level. U = Mann–Whitney test for independent samples.

Means (SD), median, and range of outcome (95% CI) and comparison between study positions.