How Much Does Pelvic Incidence Impact Sitting and Standing Positions

How Much Does Pelvic Incidence Impact Sitting and Standing Positions?

A study 1 in the European Science Journal aimed to observe if (and how) lumbo-pelvic sagittal alignment was likely affected by pelvic incidence (or PI). The results showed a correlation between PI and the change in lumbo-pelvic parameters between sitting and standing positions.

Why conduct such a study?

Over the decades, modern society has urged people to spend large amounts of their day in a sitting position; whether it’s for work, academics, or for leisure. Prolonged periods of sitting are linked to particular health concerns with nonspecific lower back pain in younger people being the most prevalent. That’s why it’s important to study the differences in spinal alignment when a person is standing and sitting as well as the effects of aging.

The current study had an objective to clarify the association of positional change to PI (pelvic incidence) and aging. The purpose was to investigate the difference in lumbo-pelvic sagittal alignment between standing and sitting positions and observe the level of association with PI and a person’s age.

The Study

A total of 253 participants were included (160 men and 93 women). They were divided into three groups. The 20 to 49 age range was the Younger Group, the 50 to 69 years being the Middle Age Group, and the 70 years and more being the Older Group. All of the participants underwent frontal and lateral radiography of the lumbar spine (this included the hip joints) while in sitting as well as standing positions.

lumbar spine

The study analyzed the lumbar lordotic angle (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), and the associations between the changes in LL (∆LL), SS (∆SS), PT (∆PT), and PI.

The Kruskal–Wallis test was administered to determine intergroup differences. The differences in lumbo-pelvic parameters between sitting and standing positions were analyzed using the t-test. The Spearman rank correlation coefficient was used to analyze correlations between the variables of lumbo-pelvic parameters.

The Results

The study shared that it couldn’t find a correlation between age and changes in lumbo-pelvic sagittal alignment between the standing and sitting positions. However, take note, these parameters correlated with age at the standing but not in the sitting position. All of the groups showed positive correlations between PI and the changes between sitting and standing positions.

What was concluded?

The study concluded that there’s a correlation when observing a change in lumbo-pelvic parameters (between the sitting and standing positions) and PI. However, the same couldn’t be said when age was involved.

The results showed that PI is an important parameter for estimating the amount of changes in lumbo-pelvic alignment between standing and sitting positions. Furthermore, the data could prove to be beneficial in understanding the link between lower back pain and how people should sit or stand (and for how long).