Two articles on PainSci cite Nourbakhsh 2002: 1. The Complete Guide to Low Back Pain 2. Psoas, So What?
PainSci notes on Nourbakhsh 2002:
The key findings:
“It appears that muscle endurance and weakness are associated with LBP and that structural factors such as the size of the lumbar lordosis, pelvic tilt, leg length discrepancy, and the length of abdominal, hamstring, and iliopsoas muscles are not associated with the occurrence of LBP.”
Nourbakhs and Arab did indeed identify a correlation between cLBP and pain and poor muscle endurance and strength, but correlation is (famously) not causation. They did not establish that the relationship is causal, or that improving these metrics is therapeutic, so note that their data is not very useful for supporting the value of core training as an intervention for back pain. And so, despite finding weak back muscles in back pain patients, it cannot by itself support the value core training (meanwhile, there's a bunch of other more relevant and recent evidence to consider).
What I think is most significant in their results is that found not even a correlation between chronic low back pain and various "structural" features. And where there is not even a correlation, there cannot be causation! So this data is useful for supporting the point that structure doesn't seem to have much to do with back pain.
original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
STUDY DESIGN: A multifactorial cross-sectional nonexperimental design.
OBJECTIVES: To collectively investigate the association among 17 mechanical factors and occurrence of low back pain (LBP).
BACKGROUND: Several physical characteristics, based on assumptions, clinical findings, and scientific experiments, have been associated with the development of LBP Controversy exists regarding the degree of association between some of these physical characteristics and LBP. Information regarding the degree of association of each factor to LBP is needed for effective prevention and appropriate treatment strategies.
METHODS AND MEASURES: A total of 600 subjects participated in this study. Subjects were categorized into 4 groups: asymptomatic men (n = 150, age [mean +/- SD] = 43 +/- 15 years), asymptomatic women (n = 150, age [mean +/- SD] = 43 +/- 13 years), men with LBP (n = 150, age [mean +/- SD] = 43 +/- 14 years), and women with LBP (n = 150, age [mean +/- SD] = 43 +/- 13 years). Seventeen physical characteristics were measured in each group and the relative association of each characteristic with LBP was assessed.
RESULTS: Among all the factors tested, endurance of the back extensor muscles had the highest association with LBP Other factors such as the length of the back extensor muscles, and the strength of the hip flexor, hip adductor, and abdominal muscles also had a significant association with LBP.
CONCLUSION: It appears that muscle endurance and weakness are associated with LBP and that structural factors such as the size of the lumbar lordosis, pelvic tilt, leg length discrepancy, and the length of abdominal, hamstring, and iliopsoas muscles are not associated with the occurrence of LBP.
- “Does unequal leg length cause back pain? A case-control study,” Grundy et al, Lancet, 1984.
- “Leg-length discrepancy is associated with low back pain among those who must stand while working,” Rannisto et al, BMC Musculoskeletal Disorders, 2015.
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- Cannabidiol (CBD) products for pain: ineffective, expensive, and with potential harms. Moore 2023 J Pain.
- Inciting events associated with lumbar disc herniation. Suri 2010 Spine J.
- Prediction of an extruded fragment in lumbar disc patients from clinical presentations. Pople 1994 Spine (Phila Pa 1976).
- Characteristics of patients with low back and leg pain seeking treatment in primary care: baseline results from the ATLAS cohort study. Konstantinou 2015 BMC Musculoskelet Disord.
- Effectiveness and cost-effectiveness of universal school-based mindfulness training compared with normal school provision in reducing risk of mental health problems and promoting well-being in adolescence: the MYRIAD cluster randomised controlled trial. Kuyken 2022 Evid Based Ment Health.