Effects of Gravity-Facilitated Traction on Intervertebral Dimensions of the Lumbar Spine

Abstract

The purpose of this study was to determine the effects of gravity-facilitated traction (inversion) on intervertebral dimensions of the lumbar spine. Fifteen normal male subjects were fully inverted for a period of 10 minutes. Vertebral separation was measured on lateral roentgenograms both pre- and postinversion by outlining the margins of the intervertebral bodies both anteriorly and posteriorly and the greatest vertical heights of the intervertebral foramina. Fine point engineering calipers were used to facilitate measurements. A student t-test for paired data was used to determine significance of separation between lumbar segments, following 10 minutes of inversion. The alpha level was set at 0.05 for statistical significance. Gravity-facilitated traction produced increased separation at all levels measured. Significant increases in total mean anterior separation, total mean posterior separation, and total mean intervertebral foraminal separation were determined. Mean anterior separation was significant at all levels except L3-L4. Mean posterior separation was significant at all levels except L1-L2 and L5-S1. Mean intervertebral foraminal separation was significant at all levels but L5-S1. If increases in intervertebral dimensions play a role in the relief of low back syndrome, then gravity-facilitated traction may be an effective moda1i;y in the treatment of this condition. J Orthop Sports Phys Ther 1985;6(5):281-288.