Bone remodelling after application of traction forces to the lumbar spine in women with chronic low back pain

Listen to Simon and Amy discuss the paper 'Bone remodelling after application of traction forces to the lumbar spine in women with chronic low back pain' published in the August 2025 issue of Bone & Joint Research.

Click here to read the paper.

Be the first to know when the next episode is live! Follow our social media accounts, @BoneJointPortal and @BoneJointRes on X, and @bonejointres on Instagram for updates!

Transcript

[00:00:00] Welcome back to another episode of AI Talks with Bone & Joint from the publishers of Bone & Joint Research. Today we're diving into the paper 'Bone remodelling after application of traction forces to the lumbar spine in women with chronic low back pain', published in August 2025 by M Ratajczak, K Kusy, D Skrypnik, M Waszak, and P Krutki.

I'm Brian and I'm joined by my co-host Lisa. 

Hello everyone. Brian, today's topic is captivating because it intertwines biomechanics, bone biology, and clinical therapy. This study essentially investigates how systematic lumbar traction applied during 20 sessions over four weeks affects bone mineral density and bone turnover markers in women suffering from chronic low back pain.

Quite an eyeopener, isn't it? 

Indeed, Lisa. Chronic low back pain is a major issue worldwide and discovering non-surgical treatments that can efficiently manage it is crucial. Let's start with the researcher's motivation for this study. 

Of [00:01:00] course, one of the main reasons for this research was to evaluate if traction therapy, a common non-surgical treatment for low back pain has any measurable effects on bone health.

Previous studies focused on the clinical benefits of lumbar traction, such as reduced pressure on spinal discs and increased space between vertebrae, but little was known about its cellular effects, particularly on bones. 

Understood. So the researchers aimed to fill that knowledge gap. They recruited 30 women with chronic low back pain who underwent 20 traction sessions over four weeks. They used dual-energy X-ray absorptiometry or DXA to assess bone mineral density and collected serum samples to analyze bone turnover markers using enzyme-linked immunosorbent assay or ELISA.

Is that correct? Lisa? 

Spot on. Brian. The traction therapy involved mechanical unloading of the spine. Each session lasted 30 minutes with a gradual increase in the traction force [00:02:00] from 25 to 30% of the women's body weight. They used a special table designed for lumbar traction. Notably, they measured total body and lumbar spine bone mineral density, both before the first session and 72 hours after the last session. 

That's a comprehensive approach. So Lisa, let's discuss the findings. What did the researchers discover? 

The results were quite enlightening. After the traction therapy, there was a noticeable decrease in bone mineral density and T-scores, especially in the L1 vertebra and the entire L1 to L4 segment. In simpler terms, the bone density in the lumbar spine decreased. Additionally, they observed an increase in the height of the lumbar vertebrae, which is quite intriguing.

Fascinating, but there's more, isn't there? 

Indeed, there is. They also noted a significant increase in the concentration of cross-linked C-telopeptide of type I collagen or CTXI, which is a bone resorption [00:03:00] marker. Simultaneously, they observed a decrease in the concentration of receptor activator for nuclear factor-kappa B ligand or RANKL.

However, the levels of Sclerostin and procollagen 1 N-terminal propeptide or P1NP did not change significantly. 

It sounds like the traction therapy increased bone turnover, but not formation. These changes suggest activation of the transforming growth factor-beta pathway involved in bone remodeling, however, it's important to note the potential clinical significance.

Despite the decrease in bone mineral density, these observations might not necessarily result in a heightened risk of bone loss. Correct? 

Exactly. Brian, the study suggests that the observed decrease in bone mineral density could be the initial phase of bone remodeling. Given that bone remodeling is a lengthy cycle future research with longer follow-up periods is necessary to fully comprehend the long-term effects. The key point here is that traction [00:04:00] therapy does impact bone tissue, and these effects should be considered when recommending this treatment for low back pain. 

That's an important consideration, Lisa.

It's also intriguing that while the traction therapy had measurable impacts, the study acknowledged limitations such as the lack of a control group and the relatively short duration. Nonetheless, this is a significant first step in understanding the mechanobiological effects of traction on bone health.

Absolutely, Brian. To summarize, this study offers valuable insights into how lumbar traction therapy affects bone metabolism. It opens new avenues for research, particularly in exploring how these mechanotransductive forces might be utilized for bone remodeling in clinical context. We encourage listeners to consider these findings and follow-up studies to better understand the wider implications.

Thank you for the engaging discussion, Lisa and thank you to our listeners for tuning into AI Talks with Bone & Joint. Stay tuned for our next episode where we'll delve into more groundbreaking research in the [00:05:00] realm of bone and joint health. 

Thanks, Brian. Goodbye everyone.