The Study: Radiographic Assessment of Spinopelvic Sagittal Alignment from Sitting to Standing Position               

The Facts:

a. In our modern society most of us spend the majority of our time sitting.

b. Most chiropractors will analyze sagittal lordosis with the subject in the standing position.

c. The authors x-rayed the lumbar spine in four different positions; sitting upright, sitting anteflexed, standing upright and standing anteflexed.

e. Two acronyms used in the study: 1)[STS] is sit-to-stand and 2) [IV ROM] for intervertebral range of motion.

f. “The motion of STS can be divided into two phases. The first phase is composed of the period that the lumbar spine and hips flex, reaching their maxima shortly after seat-off, then the lumbar spine and hips extend (sitting anteflexed). The second phase is composed of lumbar spine and hips extension to become upright during STS (standing anteflexed and standing upright)…”

 g. “Lumbar lordosis decreased in sitting, then temporarily decreased further and increased after thighs-off. Lumbar lordosis was coordinated to pelvic tilt after seat-off. The pelvis was retroverted in the sitting position and gradually anteverted during STS. Regarding IV ROM, lumbar segments after seat-off had a wider range (of motion) than before seat-off during STS…” Parenthesis ours.

Take Home:

The lumbar lordosis is decreased when sitting. It then decreases further as the patient starts to stand up. Then the lordosis increases as the patient stands up and is in full lordosis once the patient is standing fully erect. While it is somewhat tedious to read the descriptions of this movement, Fig. 2 in the full text article (link below) provides a simple set of line drawings that depict the different phases of movement.  

Reviewer's Comments:

This is a complex movement and one that is quite interesting and worth understanding. I would like to commend the authors on their efforts in this direction. 

Reviewer:  Roger Coleman DC

Editor: Mark R. Payne DC 

Reference: Suzuki H, Endo K, Sawaji Y et.al. Radiographic Assessment of Spinopelvic Sagittal Alignment from Sitting to Standing Position. Spine Surg Relat Res. 2018 Mar 15;2(4):290-293. doi: 10.22603/ssrr.2017-0074. eCollection 2018 Oct 26.  

Link to Abstract: https://www.ncbi.nlm.nih.gov/pubmed/31435536

Link to Full Text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6690107/