In today’s world it’s easy to get frustrated when we can’t get the answers we’re looking for. We tend to take certainty for granted, particularly when it comes to our health. (What do you mean you don’t know what’s causing my pain!?) Continuous advancements in medical technologies have led to vast improvements in diagnostic outcomes. These days there is an array of sophisticated tests and procedures that can diagnose even previously unknown conditions. Some of the rarest, including certain genetic disorders or autoimmune diseases, can now be diagnosed easily and with a high degree of certainty. Compared to these rare and potentially life-threatening conditions, LBP almost seems a bit drab! However, let’s not forget that LBP causes more disability than any other health condition!1 Therefore, it might surprise you to read that despite this alarming statistic, it remains a largely mysterious condition.2
As we’ve previously discussed, most cases of LBP are difficult to diagnose, so we call these episodes ‘nonspecific LBP’ (NB: LBP on this website unless otherwise stated). This condition is a diagnosis of exclusion meaning other specific causes of LBP (‘specific LBP’) must be ruled out first. And while the term ‘nonspecific LBP’ is recommended by international LBP guidelines3,4, many clinicians don’t agree with its usefulness as a diagnosis. Critics argue that lumping most LBP cases into one broad category leads to less effective treatments (since in reality nonspecific LBP probably consists of a multitude of conditions).2,5 This is why most health professionals treating LBP (eg. physical therapists, chiropractors or osteopaths) do not simply stop diagnosing once they have excluded any ‘red flags’ (signs and symptoms that could indicate something serious – more on this later). Instead, they use further questioning and examination to attempt to narrow down the source of the pain further.
What structures (tissues) are potential sources of LBP?
Since nerves are responsible for transmitting pain signals, any nerves, or tissues they innervate (‘supply’), have the potential to cause pain.6 Some examples of innervated (pain-sensitive) tissues in the lower back include muscles, joints, bones, ligaments, and connective tissues.6 Of these, joints are most commonly associated with LBP within the scientific literature. Specifically, the disc, facet joint and sacroiliac joint (SIJ). Previous studies have estimated that these structures are responsible for 39%7, 15%8, and 13%9 of LBP cases, respectively. However, the evidence supporting tests used to diagnose LBP in these studies is lacking. Even if their reliability were demonstrated, the fact that they are invasive (and therefore costly) makes them unsuitable for clinical use.5 Other commonly implicated tissues in LBP are muscles and ligaments. Tears in a muscle (strain) or ligament (sprain) due to excessive forces have long been recognised as a potential mechanism of LBP. Another muscle-related pathology, the myofascial trigger point, has also been associated with LBP.10,11 And while in theory it may be easier to consider each of these structures in isolation, in reality they are inextricably linked making this a gross simplification.
Should I get imaging for LBP?
In a word, no. While It’s true that medical imaging modalities like x-ray, CT scan and MRI are incredibly useful diagnostic tools, they only have limited effectiveness when it comes to LBP (i.e. nonspecific LBP). Even MRI, the gold standard for so many medical conditions, is rarely useful for this condition.12–15 Why is this? Rather counter-intuitively, it’s not due to a lack of resolution, but rather the number of false positives that occur. Basically, this means people without LBP often show abnormal findings (e.g. disc degeneration or bulging). For example, one review (33 studies) found that 20% of 20 year olds, 60% of 50 year olds, and 84% of 80 year olds had disc bulges.16 Another study found that half of those subjects who had not experienced LBP had abnormal findings.13 That’s a lot! This poor correlation between abnormal findings and LBP can make it virtually impossible to tell whether medical imaging findings are responsible for a person’s LBP, or if they are simply coincidental.15 This makes imaging for nonspecific LBP a waste of time and money for not only the person with LBP, but also an unnecessary burden on the healthcare system. Medical imaging can also expose people with LBP to unnecessary radiation (x-rays and CT scans), and worst of all, it can mess with their heads! More often than not these imaging techniques leave a person with a scarily long list of abnormal findings. And rather than thinking of them as ‘internal grey hairs’, often people are left feeling like ‘broken’ individuals (which unfortunately is reaffirmed every time they experience any pain/discomfort in this area). For these reasons, major LBP guidelines do NOT recommend medical imaging for nonspecific LBP.3,4,6,17 Here, here!
• REVISION: On this website ‘LBP’ refers to ‘nonspecific LBP’, unless otherwise stated.
• Despite causing more disability than any other health condition, the cause of LBP remains largely mysterious.
• Many clinicians believe the term ‘nonspecific LBP’ is unhelpful as a diagnosis, as it likely consists of a range of different conditions, and therefore warrants more than one type of treatment.
• Any tissues supplied (innervated) by nerves have the potential to cause pain, which means muscles, joints, bones, ligaments, and connective tissues are all potential sources of LBP.
• There is no universally accepted, gold standard test for diagnosing LBP.
• Medical imaging (e.g. x-ray, CT scan and MRI) is NOT usually effective for diagnosing LBP, due to a large amount of people without LBP having abnormal findings (false positives).
• Major LBP guidelines do NOT recommend imaging for LBP.
1. Hoy D, March L, Brooks P, et al. The global burden of low back pain: estimates from the Global Burden of Disease 2010 study. Ann Rheum Dis. 2014;73(6):968-974. doi:10.1136/annrheumdis-2013-204428.
2. Leboeuf-Yde C, Lauritsen JM, Lauritzen T. Why has the search for causes of low back pain largely been nonconclusive? Spine (Phila Pa 1976). 1997;22(8):877-881. doi:10.1097/00007632-199704150-00010.
3. van Tulder M, Becker A, Bekkering T, et al. European guidelines for the management of acute nonspecific low back pain in primary care (Chapter 3). Eur Spine J. 2006;15(S2):s169-s191. doi:10.1007/s00586-006-1071-2.
4. O’Connell NE, Cook CE, Wand BM, Ward SP. Clinical guidelines for low back pain: A critical review of consensus and inconsistencies across three major guidelines. Best Pract Res Clin Rheumatol. 2016;30(6):968-980. doi:10.1016/j.berh.2017.05.001.
5. Hancock MJ, Maher CG, Latimer J, et al. Systematic review of tests to identify the disc, SIJ or facet joint as the source of low back pain. Eur Spine J. 2007;16(10):1539-1550. doi:10.1007/s00586-007-0391-1.
6. Delitto A, George SZ, Professor A, et al. Low Back Pain: Clinical Practice Guidelines Linked to the International Classification of Functioning, Disability, and Health from the Orthopaedic Section of the American Physical Therapy Association Associate Professor in Physical Therapy and Orthopaedic Surgery, Program in Physical Therapy HHS Public Access. Man Ther. doi:10.2519/jospt.2012.42.4.A1.
7. Bogduk N, Spine MP-, 1995 undefined. The prevalence and clinical features of internal disc disruption in patients with chronic low back pain. drdavedecamillis.com. http://drdavedecamillis.com/articles/scans/11_InternalDiscDisruptionChronicLowBackPain_Schwarzer.pdf. Accessed April 8, 2018.
8. Schwarzer A, Aprill C, Derby R, Fortin J, Spine GK-, 1994 undefined. Clinical features of patients with pain stemming from the lumbar zygapophysial joints. Is the lumbar facet syndrome a clinical entity? europepmc.org. http://europepmc.org/abstract/med/8059268. Accessed April 8, 2018.
9. Physiological NB-J of M and, 1995 undefined. The anatomical basis for spinal pain syndromes. europepmc.org. http://europepmc.org/abstract/med/8775022. Accessed April 8, 2018.
10. Chiarotto A, Clijsen R, Fernandez-de-las-Penas C, Barbero M. Prevalence of Myofascial Trigger Points in Spinal Disorders: A Systematic Review and Meta-Analysis. Arch Phys Med Rehabil. 2016;97(2):316-337. doi:10.1016/j.apmr.2015.09.021.
11. Khing Hua N, Van der Does E. The occurrence and inter-rater reliability of myofascial trigger points in the quadratus lumborum and gluteus medius: A prospective study in non-specific low back pain patients and controls in general practice. Pain. 1994;58(3):317-323. doi:10.1016/0304-3959(94)90125-2.
12. Webster BS, Cifuentes M. Relationship of Early Magnetic Resonance Imaging for Work-Related Acute Low Back Pain With Disability and Medical Utilization Outcomes. J Occup Environ Med. 2010;52(9):900-907. doi:10.1097/JOM.0b013e3181ef7e53.
13. Savage RA, Whitehouse GH, Roberts N. The relationship between the magnetic resonance imaging appearance of the lumbar spine and low back pain, age and occupation in males. Eur Spine J. 1997;6(2):106-114. http://www.ncbi.nlm.nih.gov/pubmed/9209878. Accessed April 13, 2018.
14. Brinjikji W, Luetmer PH, Comstock B, et al. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR Am J Neuroradiol. 2015;36(4):811-816. doi:10.3174/ajnr.A4173.
15. Jensen MC, Brant-Zawadzki MN, Obuchowski N, Modic MT, Malkasian D, Ross JS. Magnetic Resonance Imaging of the Lumbar Spine in People without Back Pain. N Engl J Med. 1994;331(2):69-73. doi:10.1056/NEJM199407143310201.
16. Brinjikji W, Luetmer PH, Comstock B, et al. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR Am J Neuroradiol. 2015;36(4):811-816. doi:10.3174/ajnr.A4173.
17. O’Connell NE, Cook CE, Wand BM, Ward SP. Clinical guidelines for low back pain: A critical review of consensus and inconsistencies across three major guidelines. Best Pract Res Clin Rheumatol. 2016;30(6):968-980. doi:10.1016/j.berh.2017.05.001.