. Author manuscript; available in PMC: 2019 Jan 21.

Published in final edited form as: Eur Spine J. 2014 Mar 12;23(7):1407–1413. doi: 10.1007/s00586-014-3247-5

Table 1.

Means, Standard Deviations, and Uncertainties of Intra-observer and Inter-observer Measurements of L4–L5 Disc Height, Lumbar Lordosis, and Lumbar Spine Length for one subject in the standing condition

	Inter-observer		Intra-observer
	Mean ± SD^b	Uncertainty (%)^c	Mean ± SD^b	Uncertainty (%)^c
L4–L5 Disc height (n = 4)^a	11.6 ± 0.2 mm	1.8	11.4 ± 0.3 mm	2.9
Lumbar lordosis (n = 4)^a	62.2 ± 2.3°	3.8	59.7 ± 2.9°	4.8
Lumbar spine length (n = 4)^a	186.4 ± 1.4 mm	0.7	186.6 ± 1.2 mm	0.6

n is defined as the number of measurements done either by one independent observer on four separate occasions (Intra-observer) or by four independent observers (Inter-observer)

SD stands for standard deviation from the mean

Uncertainty (%) was calculated as the standard deviation divided by the mean and then multiplied by 100