Table 2.

In vivo geometry and strain of human lumbar IVDs

		L1/2	L2/3		L3/4	L4/5	L5/S1	Reference
Anterior–posterior disk length						30.4 ± 4.5 mm	30.0 ± 4.4 mm	Zhong et al. [50]
34 mm	34 mm		33 mm	33 mm	31 mm	Pearcy and Tibrewal [51]
Disk height	AAF	8 mm	11 mm		12.5 mm	14 mm	13 mm	Pearcy and Tibrewal [51]
					10.27 ± 2.28 mm		Miao et al. [53]
	PAF	4 mm	4.5 mm		4.5 mm	5.5 mm	4.5 mm	Pearcy and Tibrewal [51]
				6.07 ± 1.97		Miao et al. [53]
Max Flex ROM		7 ± 4 deg	9.2 ± 3.9 deg		9.5 ± 4.4 deg	9.3 ± 5.4 deg	6.3 ± 5.4 deg	Lee et al. [46]
					6.1 ± 1.5 deg	9.0 ± 2.1 deg	7.3 ± 1.1 deg	Nagel et al. [47]
			12.99 deg		10.91 deg	12.69 deg	10.33 deg	Aiyangar et al. [52]
		8 ± 5 deg	10 ± 2 deg		PAF: X = 3.6 ± 1.6 mm, Y = 4.1 ± 1.2 mm, 12 ± 1 deg	PAF: X = 4.5 ± 1.2 mm, Y = 5.4 ± 1.0 mm, 13 ± 4 deg	PAF: X = 1.1 ± 0.9 mm, Y = 4.2 ± 1.1 mm, 9 ± 6 deg	Pearcy et al. [44] and Kanayama et al. [49]
9.4 deg	9.2 deg		10.3 deg	9.5 deg	9.5 deg	Stokes [54]
Max Ext. ROM				PAF: X = 0.6 ± 0.6 mm, Y = 0.1 ± 0.8 mm		PAF: X = 0.1 ± 0.2 mm, Y = 0.0 ± 0.1 mm	PAF: X = 2.6 ± 2.6 mm, Y = 3.7 ± 1.9 mm	Kanayama et al. [49]
5 ± 2 deg	3 ± 2 deg	1 ± 1 deg		2 ± 1 deg	5 ± 4 deg	Pearcy et al. [44]
Max lateral bending ROM			2.9 ± 2.4 deg	3.4 ± 2.1 deg		4.7 ± 2.4 deg		Li et al. [55]
Max Ext. ROM		5 ± 2 deg	3 ± 2 deg		1 ± 1 deg	2 ± 1 deg	5 ± 4 deg	Pearcy et al. [44]
Max lateral bending ROM			2.9 ± 2.4 deg		3.4 ± 2.1 deg	4.7 ± 2.4 deg		Li et al. [55]
10 deg	11 deg		10 deg	6 deg	3 deg	Pearcy and Tibrewal [51]
Max torsion ROM			3.2 ± 1.9 deg		2.8 ± 1.7 deg			Xia et al. [56]
			2.5 ± 2.3 deg		2.4 ± 2.6 deg	2.9 ± 2.1 deg		Li et al. [55]
2 deg	2 deg		3 deg	3 deg	2 deg	Pearcy and Tibrewal [45]
Strain at full flexion					AAF = −25%	AAF = −29%	AAF = −24%	Nagel et al. [48]
		PAF = +50%	PAF = +65%	PAF = +29%
			AAF = −17 ± 8%PAF = +26 ± 9%Shear 18 ± 16%		AAF = −15 ± 10%PAF = +22 ± 13%Shear 29 ± 17%			Wang et al. [57]

AAF = Anterior AF; PAF = Posterior AF; − = Compressive; + = Tensile; ROM = Range of motion.