The effect of running-induced intervertebral disc compression on thoracolumbar vertebral column mobility in young, healthy males.

Several previous studies have shown that intervertebral discs compress under the forces of axial loading, but few thus far have examined the effect of disc compression on the mobility of the spine. The purpose of this study was to determine if decreases in disc height and the mobility of the vertebral column between T7 and S2 in young, healthy males occurred after running and if there was a positive correlation between these two variables. The population of interest consisted of 30 18- to 25-year-old healthy males who ran 10-70 miles per week, all of whom had no previous or current back pathology. Following an 8-minute warm-up on a Fitron bicycle, vertebral column height (from C7 to S2) and vertebral column lateral flexion to the left (from T7 to S2) were measured. Directly following measurement, each subject ran 7 miles on a predetermined flat, paved course at a comfortable pace. Immediately following the run, each subject was measured again for vertebral column height and lateral flexion to the left. Paired t-tests revealed significant decreases in both vertebral column height and left lateral flexion. Pearson's r revealed only a small correlation between the decreases in these two variables. Although the correlation was not significant, the decreases in both variables may have implications for physical therapy with respect to range of motion measurements, because range of motion may change with varied amounts of disc compression, and for exercise programs for patients with various back pathologies, because certain back pathologies may be influenced by the degree of disc compression. J Orthop Sports Phys Ther 1992;16(1):19-24.