Cervical spine curvature varies between subjects, and can vary within a subject towards increased lordosis with increasing age. Understanding the effect of cervical spine curvature is important to assess injury risk in impact scenarios for the aging population. In the present study the GHBMC 50th percentile occupant male neck model was morphed into 3 different postures;​ 75 YO 50th percentile with average lordosis, 26 YO with superior and inferior Bézier angles reduced by 5 degrees, and 75 YO with superior and inferior Bézier angles increased by 5 degrees, representing a range of cervical spine curvatures. The C4-C5 motion segment in the modified postures was extracted and evaluated under flexion, extension and tension loading scenarios. No significant changes in kinetics and kinematics were identified for tension and flexion loading. However, significant changes were observed in the kinetic and kinematic response for extension loading at the larger and smaller spine curvatures, with similar response for the 26 YO 50th percentile and 75 YO 50th percentile models. The present study identified that average changes in curvature with age did not significantly change the motion segment response, while larger variations within the population values did affect the response of the motion segment, primarily in extension.