Publications

Background: Chronic low back pain (LBP) is common among individuals performing intensive physical labor, particularly in rural areas. This study evaluated the immediate effects of lumbar unloading, with or without heat, on paraspinal muscle properties in physically active adults with chronic LBP.

Methods: Forty-two adults with chronic LBP were randomly assigned to lumbar unloading alone (Group 1) or unloading combined with heat (Group 2). Paraspinal muscle tone, stiffness, and logarithmic decrement were assessed using MyotonPRO before and immediately after a single 20-minute intervention. Pre–post changes were compared between groups.

Results: Group 1 showed small increases, whereas Group 2 showed small decreases in all parameters. No significant between-group differences were found for tone (Δ = −0.39 Hz, 95% CI: −0.97 to 0.18; p = 0.171), stiffness (Δ = −7.00 N/m, 95% CI: −23.31 to 9.31; p = 0.391), or logarithmic decrement (Δ = −0.05, 95% CI: −0.12 to 0.02; p = 0.162). Effect sizes were small (Cohen’s d = −0.43, −0.27, and −0.44, respectively).

Conclusions: A single 20-minute session of lumbar unloading, with or without heat, did not produce significant between-group differences in paraspinal muscle properties. The reductions observed in the heat group are exploratory and do not demonstrate a beneficial effect of heat. As only immediate biomechanical responses were assessed and no validated clinical outcomes were included, the clinical significance of the findings remains unclear. Further studies with larger samples, longer or repeated interventions, appropriate controls, and clinical outcomes are warranted.

Keywords: muscle tonus, spinal diseases, physical activity, recovery, rural health

A single 20-minute session of lumbar unloading, performed either alone or in combination with a thermal stimulus, did not result in statistically significant between-group differences in pre–post changes in paraspinal muscle tone, stiffness, or logarithmic decrement. Although the heat group showed descriptive reductions in all three biomechanical parameters, these findings do not provide evidence of an additional beneficial effect of heat application and should be interpreted as preliminary and hypothesis-generating.

Because the study assessed only immediate biomechanical responses and did not include validated measures of pain, disability, functional performance, or quality of life, the clinical significance of the observed changes cannot be established. Further randomized studies with larger samples, appropriate control conditions, repeated or longer interventions, longer follow-up, and clinically relevant patient-reported outcomes are warranted to determine whether these approaches can produce reproducible and clinically meaningful effects in individuals with chronic low back pain.