Pain Relief Blog

Non-specific low back pain: a brief review on the risk factors, diagnosis, and management

Author: Dr. Faisal Hayat, MBBS

Definition

The sensation of pain located below the costal margin and above the inferior gluteal folds, with or without leg pain, not attributed to a recognizable, known specific cause, is called non-specific low back pain (NLBP).

Introduction

Low back pain (LBP) is one of the most common musculoskeletal health problems with the highest prevalence in the adult population. It is the main contributor to years lived with disability. Low back pain (LBP) is classified into acute, subacute, chronic, and non-specific low back pain. LBP imposes an enormous economic burden on healthcare systems annually and affects individuals’ daily lives.

Non-specific low back pain (NLBP) is the most common type, representing about 90–95% of LBP cases.[1]
It is responsible for a high index of work absenteeism and early retirement. It affects 70–80% of the population of developed countries at some stage during their lifetime, representing the leading cause of movement restriction, long-term incapacity, and reduction in the quality of life.
It has an estimated cost of 1.7 and 2.1% of the gross domestic product in Europe, while it is about $ 86.7 billion in a year, 2013 in the US.[2] Hence, effective strategies are necessary to minimize the impact of LBP.

What are the causes and risk factors for non-specific low back pain (NLBP)?

Non-specific low back pain is a symptom of an unknown cause. Many factors have been identified as a possible cause or as being able to affect its development and subsequent course.

Triage aims to exclude those cases in which the pain arises from either problem beyond the lumbar spine (e.g., leaking aortic aneurysm); specific disorders affecting the lumbar spine (e.g., epidural abscess, compression fracture, spondyloarthropathy, malignancy, cauda equina syndrome); or radicular pain, radiculopathy, or spinal canal stenosis. The remaining cases are non-specific low back pain.

Many cross-sectional studies have reported a significant association between low back pain and degeneration of the lumbar discs seen with clinical imaging. A systematic review said that, at the individual level, none of the lesions identified by MRI could be established as the cause of low back pain because such MRI abnormalities are widespread in asymptomatic individuals.[3]
A prospective case-control study has proved the possible pathophysiological role of tumor necrosis factor α (TNFα) in low back pain.[4]
The role of nerve growth factors extracted from degenerative nucleus pulposus in pain transmission was suggested by experimental research because nerve growth factor promotes axonal growth and induce substance P production.
Some mechanical factors may have a role in low back pain. However, eight systematic reviews with the Bradford-Hill causation criteria suggested that the role of occupational sitting, awkward postures, standing and walking, manual handling or assisting patients, pushing or pulling, bending and twisting, lifting, or carrying in low back pain is not independent in the populations of workers studied.[5]
Another study proves that people who are overweight or obese have an increased risk of low back pain.[6]
Interleukin-1 gene cluster polymorphisms are associated with Modic changes and might have a pathogenic role in low back pain.

How will you diagnose the non-specific low back pain?

The diagnosis of non-specific low back pain is dependent on the clinician being satisfied that there is no specific pathological cause. Some patients with non-specific low back pain (NLBP) may also feel pain in their upper legs, but the low back pain usually predominates. Several structures, including the joints, discs, and connective tissues, may contribute to symptoms of low back pain (LBP).

In many patients, increased pain on coughing, sneezing, or straining, positive straight leg raising, and crossed straight leg raising can be used to predict nerve root compression on MRI.
Most patients seeking surgical treatment for lumbar stenosis may have subjective symptoms only, such as pain during walking.
Females, age >70 years, substantial trauma, and prolonged use of steroids are significantly associated with vertebral fracture.
In patients with low back pain, MRI has many uses: predictive, diagnostic, prognostic, assessment of recovery, and occupational screening. However, most recent guidelines advise that all imaging studies should be reserved for patients with progressive neurological deficits or suspected serious underlying causes.

How will you manage the patient with non-specific low back pain (NLBP)?

No specific treatments can be provided for non-specific low back pain because it does not have a known pathoanatomical cause. In managing non-specific low back pain, you should initially distinguish the patients with severe or non-spinal disorders from those with the pain of musculoskeletal origin, particularly having red flags.

The red flags include weight loss, previous history of tumor, night pain, age >50 years, trauma, fever, saddle anesthesia, difficulty with micturition, iv drug misuse, progressive neurological disturbances, and use of systemic steroids.

Once the red flags or severe disorders have been ruled out, the next priority is identifying patients with radicular pain. Imaging as the first-line modality should be discouraged. The treatment modalities used for non-specific low back pain (NLBP) are following

Educate and reassure the patient
Exercises, manual therapies, including massage, mobilization, and manipulations.
Other non-pharmacological interventions Including, interferential, laser, lumbar supports, pulsed electromagnetic therapies (PEMF), transcutaneous electrical nerve stimulation (TENS), traction, and ultrasound.
Psychological interventions like cognitive behavioral therapy and self-management. Combined physical and psychological interventions (CPP) in some types of back school and multidisciplinary rehabilitation programs
Pharmacological interventions include antidepressants, non-steroidal anti-inflammatory drugs (NSAIDs), opioids, and paracetamol.
Invasive or surgical procedures include acupuncture, electro-acupuncture, nerve blocks, neuro-reflex-therapy, percutaneous electrical nerve stimulation (PENS), injection of therapeutic substance into the spine.

Acute management of NLBP

The main components of non-specific low back pain (NLBP) management are; educating and reassuring the patient, analgesic medicines, and non-pharmacological therapies.

Explain to the patient that degenerative changes are commonly present and increase with age. The next step is to educate the patient about the disease, and the likely outcome, explain that little or no medical treatment is required for most patients. Misconceptions about non-specific low back pain (NLBP) are pretty common so, identify and address them. A systematic review concludes that patient education reduces the fears and concerns of the patient and reduces subsequent primary care visits.[7]
Some guidelines traditionally endorse the WHO analgesic ladder, beginning with more straightforward options before more powerful analgesics.[8] The 2016 UK NICE published guidelines for managing low back pain. It advised only two options: oral NSAIDs and the use of a weak opioid (with or without paracetamol) if the patient does not tolerate or respond to an NSAID.[9]
Non-pharmacological therapies include manual therapy, exercise, massage, and acupuncture.

Long-term management of NLBP

The management of persistent low back pain emphasizes non-pharmacological therapies and greater consideration of the management of comorbidities such as depression.

Systematic reviews publish the effectiveness of NSAIDs [10] and opioids for patients with chronic low back pain,[11] but not paracetamol,[12] muscle relaxants,[13] tricyclic antidepressants,[14] or neuromodulators such as gabapentin or pregabalin.[15]
The 2016 NICE guidelines completely dispense with the notion of an analgesic ladder and endorse oral NSAIDs only.
Non-pharmacological treatments are preferred over pharmacological options in managing persistent non-specific low back pain. The American College of Physicians and the American Pain Society guideline endorses manual therapy, exercise therapy, massage, acupuncture, yoga, cognitive behavioral therapy, and intensive interdisciplinary treatment.[16]
The 2016 NICE draft guideline endorses self-management, exercise, manual therapy, psychological therapies, combined physical and psychological programs, return-to-work programs, and radiofrequency denervation.

Role of PEMF to relieve NLBP

A recent randomized controlled trial with the title ” A pulsed electromagnetic field therapy device for non-specific low back pain” has proved the safety and efficacy of the PEMF device in relieving low back pain. It has improved quality of life and is effective in non-specific low back pain (NLBP) management.[17]

References

Bardin LD, King P, Maher CG (2017) Diagnostic triage for low back pain: a practical approach for primary care. Med J Aust 206(6):268–273
Dieleman, J. L., Baral, R., Birger, M., Bui, A. L., Bulchis, A., Chapin, A., et al. (2016). US spending on personal health care and public health, 1996-2013. JAMA 316, 2627–2646.
Endean A, Palmer KT, Coggon D. Potential of magnetic resonance imaging findings to refine case definition for mechanical low back pain in epidemiological studies: a systematic review. Spine (Phila Pa 1976) 2011; 36: 160–69.
Wang H, Schiltenwolf M, Buchner M. The role of TNF-alpha in patients with chronic low back pain—a prospective comparative longitudinal study. Clin J Pain 2008; 24: 273–78.
Roffey DM, Wai EK, Bishop P, Kwon BK, Dagenais S. Causal assessment of occupational sitting and low back pain: results of a systematic review. Spine J 2010; 10: 252–61.
Shiri R, Karppinen J, Leino-Arjas P, Solovieva S, Viikari-Juntura E. The association between obesity and low back pain: a meta-analysis. Am J Epidemiol 2010; 171: 135–54.
Traeger AC, Hubscher M, Henschke N, Moseley GL, Lee H, McAuley JH. Effect of primary care-based education on reassurance in patients with acute low back pain: systematic review and meta-analysis. JAMA Intern Med 2015; 175: 733–43.
Koes BW, van Tulder M, Lin CW, Macedo LG, McAuley J, Maher C. An updated overview of clinical guidelines for the management of non-specific low back pain in primary care. Eur Spine J 2010; 19: 2075–94.
National Institute for Health and Care Excellence. Non-specific low back pain and sciatica: management. NICE guideline: short version. Draft for consultation, March 2016. https://www.nice.org.uk.
Enthoven WT, Roelofs PD, Deyo RA, van Tulder MW, Koes BW. Non-steroidal anti-inflammatory drugs for chronic low back pain. Cochrane Database Syst Rev 2016; 2: CD012087.
Chaparro LE, Furlan AD, Deshpande A, Mailis-Gagnon A, Atlas S, Turk DC. Opioids compared with placebo or other treatments for chronic low back pain: an update of the Cochrane review. Spine (Phila Pa 1976) 2014; 39: 556–63.
Machado GC, Maher CG, Ferreira PH, et al. Efficacy and safety of paracetamol for spinal pain and osteoarthritis: systematic review and meta-analysis of randomized placebo-controlled trials. BMJ 2015; 350: h1225.
Abdel Shaheed C, Maher C, Williams KA, McLachlan AJ. Efficacy and tolerability of muscle relaxants for low back pain: systematic review and meta-analysis. Eur J Pain 2016; published online Jun 22.
Urquhart DM, Hoving JL, Assendelft WW, Roland M, van Tulder MW. Antidepressants for nonspecific low back pain. Cochrane Database Syst Rev 2008; 1: CD001703.
Atkinson JH, Slater MA, Capparelli EV, et al. A randomized controlled trial of gabapentin for chronic low back pain with and without a radiating component. Pain 2016; 157: 1499–507.
Chou R, Qaseem A, Snow V, et al. Diagnosis and treatment of low back pain: a joint clinical practice guideline from the American College of Physicians and the American Pain Society. Ann Intern Med 2007; 147: 478–91.
Lisi AJ, Scheinowitz M, Saporito R, Onorato A. A Pulsed Electromagnetic Field Therapy Device for Non-Specific Low Back Pain: A Pilot Randomized Controlled Trial. Pain Ther. 2019 Jun;8(1):133-140. DOI: 10.1007/s40122-019-0119-z. Epub 2019 Mar 12. PMID: 30868475; PMCID: PMC6513933.

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