Using two-dimensional video analysis, the effects of age and gender on functional rotation and lateral flexion of the back and neck were examined in 110 subjects. Equal numbers of male and female subjects were blocked into five age groups for a lifespan analysis: 6-8, 12-15, 20-30, 40-50, 60-80 years. Each subject performed three movements: a neck rotation, neck and back rotation, and a neck and back lateral flexion. The degree of movement was determined by the Peak Two-Dimensional Motion Measurement Analysis System. No significant gender difference was found for any of the movements tested though spinal mobility decreased significantly with age and became more variable. The oldest age group was significantly less flexible than all younger age groups on all three movements. Significant differences were also found between the youngest age group and the middle adults on all movements.