A functional status measure was developed by adding 5 items to the Health Assessment Questionnaire (HAQ-S), and compared to anthropometric measures of spinal mobility. Forty-four patients with spondylitis were evaluated by the HAQ-S and measures of spine flexibility (finger-to-floor, Smythe test, neck rotation, and chest expansion). Modification of the HAQ raised the mean difficulty score by 29% from 0.38 (SD = 0.49) to 0.49 (SD = 0.51), indicating increased ability to capture functional limitations. Neck rotation correlated most strongly with the HAQ-S score (r = -0.57), which suggests an important role for this measure in clinical management and followup of spondylitis.