Figure 5From: Quantifying intervertebral disc mechanics: a new definition of the neutral zone Scatter plot of the Neutral Zone magnitudes. The NZ calculated by the double sigmoid function (x-axis) as compared to the angulation difference as defined by Wilke (y-axis). Before the conditioning by continuous axial compression, the NZ as determined with the double sigmoid function is considerably larger than the angulation difference (closed circles). After a seven hours compression period, the values are more comparable (open circles). The thin line represents identity.Back to article page