The impact of compressive force magnitude on the in vitro neutral zone range and passive stiffness during a flexion–extension range of motion test

摘要

The objective of this work was to examine the influence of compressive force magnitude on a functional spinal unit’s (FSU) flexion–extension neutral zone measured during pure moment (PM) tests. Each porcine cervical FSU received four repeats of a PM test with 10, 300, 900 and 1,800?N of compressive force, in a randomized order. Increasing the magnitude of compression significantly decreased the neutral zone range (p ??0.001), while increasing passive stiffness (p ??0.001). The flexion limit at 10?N was significantly lower (p ??0.05) than the other loading conditions. Reporting the compressive force magnitude is important when posture is a standardized experimental factor considered in the design of in vitro spine biomechanics studies.