Table 3.

3D joint kinematic measurement accuracy (bias and precision) during axial rotation. Data is from 2 subjects performing 7 trials of axial rotation. For each of the 3D joint kinematic variables, bias and precision were calculated as described in Table 1.

Measurement	Bias			Precision
	Above Fusion	Fused	Below Fusion	Above Fusion	Fused	Below Fusion
Medial-lateral translation (mm)	0.1 ± 1.1	0.5 ± 0.8	0.6 ± 0.4*	0.2 ± 0.1	0.3 ± 0.1	0.2 ± 0.1
Superior-inferior translation (mm)	−0.2 ± 0.8	0.3 ± 0.2*	0.2 ± 0.3	0.6 ± 0.4	0.6 ± 0.6	0.5 ± 0.5
Anterior-posterior translation (mm)	0.5 ± 0.5	0.7 ± 0.1*	1.0 ± 1.8	0.6 ± 0.1	0.4 ± 0.1	0.4 ± 0.2
Flexion-extension (deg)	1.7 ± 1.1*	−0.8 ± 1.1	−1.1 ± 2.6	1.8 ± 0.1	1.7 ± 0.3	1.3 ± 0.8
Axial rotation (deg)	0.3 ± 0.5	0.7 ± 2.7	−0.1 ± 0.8	1.2 ± 0.3	1.2 ± 0.1	0.8 ± 0.2
Lateral bend (deg)	−0.6 ± 0.5*	0.6 ± 3.5	−0.1 ± 0.9	0.9 ± 0.1	1.1 ± 0.1	0.7 ± 0.3

^*indicates bias statistically different from zero.