Letter to “Clinical Outcomes of a New Foot-Worn Non-Invasive Biomechanical Intervention Compared to Traditional Physical Therapy in Patients With Chronic Low Back Pain. A Randomized Clinical Trial”

To the Editor,

We read with great interest the article by Veeramachaneni et al entitled “Clinical Outcomes of a New Foot-Worn Non-Invasive Biomechanical Intervention Compared to Traditional Physical Therapy in Patients With Chronic Low Back Pain. A Randomized Clinical Trial”. ¹ The authors should be commended for conducting a well-designed randomized controlled trial on an important clinical problem. Nevertheless, several methodological considerations warrant further discussion to better contextualize the findings and inform future research.

First, the study did not examine whether the intervention influences spinal sagittal alignment. Although significant improvements in pain, function, and gait velocity were observed, the absence of radiographic assessment leaves unanswered whether the device modifies spinopelvic parameters such as lumbar lordosis, pelvic tilt, sacral slope, or sagittal vertical axis. Given the established association between sagittal balance and outcomes in chronic low back pain, ² future trials should incorporate radiographic or low-dose EOS imaging. This would help determine whether clinical benefits are mediated, at least in part, by changes in global or regional sagittal alignment, thereby identifying subgroups most likely to benefit.

Second, emerging evidence highlights the importance of paraspinal muscle quality, particularly fatty infiltration of the multifidus and erector spinae, in the pathogenesis and persistence of chronic low back pain. ³ Such fatty degeneration compromises spinal stability, correlates with sagittal imbalance, and is linked to poorer outcomes. ⁴ Since the device is designed to alter gait mechanics and provide neuromuscular retraining, long-term use may conceivably attenuate paraspinal muscle degeneration by enhancing dynamic stabilization. Future studies integrating MRI-based muscle composition analysis would therefore be valuable to clarify whether improvements in pain and function are related to muscle quality as well as spinal alignment.

Finally, the study did not address medication use, particularly analgesics. In the context of the opioid crisis, it is critical to assess whether this intervention reduces reliance on pharmacological pain management. Prospective monitoring of analgesic and opioid consumption as a secondary outcome would strengthen the clinical relevance of future trials, offering insight into the intervention’s potential opioid-sparing effect.

In summary, this randomized trial provides promising evidence for a novel foot-worn biomechanical intervention in the management of chronic low back pain. Future research should expand upon these findings by addressing patient heterogeneity, adherence monitoring, biomechanical and muscular mechanisms, and potential reductions in medication use, while also considering cost-effectiveness to fully establish its role in the therapeutic landscape.