Background & Aims

Low back pain stands as the primary cause of years lived with disability in many countries, affecting individuals across various age groups. Moreover, it is accountable for a decline in quality of life. It has severe negative economic implications, anticipating a surge in case numbers and associated expenses in the forthcoming years. Approximately 90% of cases of lower back pain are categorized as nonspecific, and a probable mechanism is illustrated, signifying that the perception of pain can exist without an injury. Chronic pain can induce physiological adjustments in the autonomic system, leading to alterations, including changes in skin electrical impedance and pain intensity. Given this context, the objective was to investigate a correlation between the electrical impedance of the torso and the perception of pressure pain and pain intensity during movement in individuals with nonspecific chronic low back pain.

Methods

This study follows a cross-sectional design and received approval from the Human Research Ethics Committee of the institution: Approval Number 5.542.592. Inclusion criteria involved individuals with nonspecific low back pain, aged between 30 and 59, representing both genders. Exclusion criteria comprised individuals with cardiovascular problems, diabetes, pregnant individuals, or those with other chronic pains. Assessment instruments included the Numerical Rating Scale (NRS), pressure pain threshold (PPT) conducted 2 cm adjacent to the right and left of the fifth lumbar vertebra (L5), and bioimpedance measurements using the device Inbody S10.

Results

Pearson’s correlation coefficient was utilized to assess the magnitude of the correlation between the measures. The final study sample comprised 46 participants, mostly female volunteers (54%). The volunteers had an age average of 44.6 (SD=6.67) years, an average NRS of 6.1(SD=2.05) points, an average pain duration of 55.4 months (SD=63.2) and an average trunk impedance of 26.8 Ohms (SD=3,64).
The study yielded the following results: a weak and negative association between the PPT on the right side of L5 and electrical impedance of the torso at 50 kHz (rs = ?0.318, p = 0.031), a weak and negative association between the PPT on the left side of L5 and the electrical impedance of the torso at 50 kHz (rs = ?0.361, p = 0.014), and an association between the NRS and electrical impedance of the torso at 50 kHz (rs = ?0.380, p = 0.0009).

Conclusions

The electrical impedance of the torso is correlated with the pressure pain threshold of the L5 vertebra and the NRS in individuals with chronic low back pain.

References

Ferreira, Manuela L., et al. “Global, regional, and national burden of low back pain, 1990–2020, its attributable risk factors, and projections to 2050: a systematic analysis of the Global Burden of Disease Study 2021.” The Lancet Rheumatology 5.6 (2023): e316-e329.

Dibai-Filho, Almir Vieira, et al. “Electrical impedance of the torso is associated with the pressure pain threshold on myofascial trigger points in patients with chronic neck pain: A cross-sectional study.” Journal of back and musculoskeletal rehabilitation 31.2 (2018): 275-284.

Amiri, Mohammadreza, et al. “Pressure pain threshold in patients with chronic pain: a systematic review and meta-analysis.” American journal of physical medicine & rehabilitation 100.7 (2021): 656-674.

Presenting Author

Jocassia Pinheiro

Poster Authors

Marina Figueiredo Magalhães

graduated student

Ribeirão Preto Medical School, University of São Paulo

Lead Author

Jocassia Pinheiro

Universidade de São Paulo (USP)

Lead Author

Rinaldo Roberto de Jesus Guirro

Universidade de São Paulo

Lead Author

Topics

  • Assessment and Diagnosis