Background and purpose of study: Intervertebral disc height loss is associated with decreased spinal stability and increased loading on spinal structures, which may be a source of back pain. In the past, total stature change, measured using stadiometry, has often been used as an indication of disc height loss and as an index of the load on the spine. The aim of this study was to use an upright MRI scanner to investigate the changes in lumbar disc dimensions following a short-term loading protocol. It was hypothesized that there would be a linear relationship between the loss in total lumbar disc height and a measure of stature change obtained from a stadiometer.

Method and Results: Thirteen participants with no history of low back pain were recruited. Stadiometer measurements and MRI images of the lumbar spine were obtained both before and after 15-minutes of walking wearing a weighted vest. Contrary to the original hypothesis, no correlation (r = 0.32) was found between total disc height loss measured via MRI and via stadiometry. However a correlation (r = 0.54) was found between stature loss measured on the stadiometer and the decrease in posterior spine length.

Conclusion: The results suggest that stadiometry should not be used to quantify the change in individual disc height or individual disc compression force. However, the correlation with the composite measure of spinal length does offer support to the use of stadiometry to assess the overall effect of loading.