The pattern of chest and spinal mobility in ankylosing spondylitis. An objective clinical study of 106 patients.

Abstract

The pattern of chest expansion and spinal mobility (anterior flexion, lateral flexion, and extension) has been studied in 106 patients with ankylosing spondylitis. New objective clinical methods were used to measure spinal mobility; the measurements from patients were compared with those obtained from 237 normal controls. Traditional subjective observation that chest and spinal mobility are limited in ankylosing spondylitis has been confirmed objectively after correcting the data for age and sex. No difference in pattern of chest and spinal mobility was noted between patients with uncomplicated spondylitis and those with spondylitis associated with psoriasis, ulcerative colitis, Crohn's disease, and Reiter's disease. On a clinical basis four patterns of spondylitis were delineated: (1) pain-free and normal chest and spinal mobility (8–6%); (2) painful but normal mobility (14.1%); (3) painful and restricted mobility (66.3%); and (4) relatively pain-free but completely limited mobility (10.8%). The scatter of chest and spinal mobility in patients was considerable, and extensive overlap into the normal range occurred. The degree of overlap, and therefore the high yield of false negative results, weaken the value of clinical measurements as accurate indices of ankylosing spondylitis. Contrasted with normal controls, a correlation study in patients with spondylitis revealed close relationships (1) between chest expansion and all three planes of spinal mobility, and (2) between individual planes of spinal mobility. It is suggested, therefore, that for epidemiological studies of ankylosing spondylitis, measurement of only one of these parameters should be sufficient. In order to secure the best clinical differentiation between spondylitis and disorders of the lumbar disc, lateral spinal flexion is probably the measurement of choice. In addition to their value in differential diagnosis, chest and spinal mobility are also useful in the assessment of progress and therapy.