The flexion-extension profile of lumbar spine in 100 healthy volunteers

Study Design. Dynamic lumbar flexion-extension motions were assessed by an electrogoniometer and a videofluoroscopy unit simultaneously. Objectives. The aims of this study were to assess the motion profile of lumbar spine in different genders and age groups and to assess their differences. Summary of Backgrounds Data. The dynamic lumbar flexion-extension motions analysis method has been developed and validated. However, data profile of the spinal motions of healthy volunteers has not been established. Methods. A total of 100 healthy volunteers, including 50 men and 50 women, were recruited. They were then divided into four equal groups, following their age ranges of 21 to 30 years, 31 to 40 years, 41 to 50 years, and 51 years and older. Lumbar flexion - extension motion was assessed with an electrogoniometer and videofluoroscopy simultaneously. Radiologic images of the lumbar spine were captured during flexion - extension in 10degrees intervals. Intervertebral flexion - extension (IVFE) of each vertebral level was calculated. The spinal motion of different genders was compared segment by segment with independent t test. The spinal motion of different age groups was compared with one-way analysis of variance. Results. A linear-liked pattern of the IVFE curves was observed in different genders and age groups. No statistically significant difference in the pattern of motion was found between genders. However, statistically significant difference in the slope of IVFE curves was found at all lumbar levels in subjects whose age was 51 years or older ( P < 0.05). Conclusions. Assessment of motion profile was found to be helpful for the identification of spinal disorders in clinical practice. Because of the normal variation of spinal motion of subjects in different age ranges, interpretation of spinal motion disorders should be careful. Although the sample size in this study was limited, the database generated might be useful to assist the diagnosis of spinal "instability" in the future.