Figure 1: Subject disposition and study flow (). GSA: Gravity Stress Analyzer. HIT-6: Headache Impact Test-6. HRQoL: Health Related Quality of Life. MIDAS: Migraine Disability Assessment Scale. MSQL: Migraine-Specific Quality of Life Measure. NUCCA: National Upper Cervical Chiropractic Association. PC-MRI: Phase Contrast Magnetic Resonance Imaging. VAS: Visual Analog Scale.