Low back pain

Vlaeyen JWS, Maher CG, Wiech K et al. Low back pain. Nat Rev Dis Primers. 2018 Dec 13;4(1):52. doi: 10.1038/s41572-018-0052-1.

  • The nonbiological risk factors include negative beliefs and expectations about pain, emotional responses, pain behaviors, perception about the relationship between pain, health, and work and social obstacles.
  • Systemic reviews of risk factors for low back pain and sciatica have suggested that physical risk factors (such as prolonged standing and lifting heavy weights), an unhealthy lifestyles ( such as smoking and obesity) and psychological factors (such as distress and the expectations that pain indicates bodily harm or injury) increase the risk of a back pain episode. In addition, manual tasks involving, for example, heavy loads, awkward postures and lifting objects not close to the body, as well as being distracted during an activity or task, were identified by patients as triggers of a new episode of sudden-onset acute low back pain.
  • A back pain is a symptoms, the aetiology could be influenced by numerous factors, including local and systemic factors, such as structural failure of the musculoskeletal tissues; inflammatory and immunological responses; genetic predisposition; excessive static or dynamic loading; emotional state; behavioural and environmental factors; beliefs and expectations about what might happen with back pain in the future and whether it can be controlled; the social consequences following the expression of pain ( increased empathy or rejection); and social system.
  • In cohort studies assessing the exposure to long-term suspected risk factors for back pain, job dissatisfaction and emotional distress were predictive of new back pain claims but not the physical aspects of work( such as spinal load) or the physical capacities of the worker(such as back muscle strength)
  • Predictions or expectations of the occurrence, magnitude and consequences of pain are generated on the basis of prior information about the state of the body(such as ‘this activity is likely to harm my back`). These predictions are influenced by a generative model of na individual’s own body (such as ‘my back is vulnerable’) and other metacognitions about health and illness (such as ‘there is nothing I can do to change my pain’ and ‘pain is always a sign fo harm`). Predictions or expectations of pain can also be generated by an individual’s own experiences, in additions to verbal information and observations of what happens to other people in similar contexts. From a Bayesian prospective, expectations of pain are compared with the actual sensation, which can confirm the prediction and the belief ( a match) or , alternatively, lead to a prediction error that urges the individual to update these beliefs(a mismatch). An individual’ homeostatic goal is to minimize prediction errors and to increase the accuracy of predictions. Whether the prediction is corrected or not largely depends on the relative precision of the sensory input and the expectation of pain. If the sensory input is less precise, the perception will be more in line with the prior expectations and vice versa. Given the ambiguity and imprecise nature of low back pain, expectation of back pain might be enough to increase its intensity or perceive inoccuous sensation as painful.
  • In patients with back pain, misinterpretation of pain as a sign of harm usually lead to pain-related fear and avoidance behaviours that further fuel the disability, depression and anxiety.
  • For example, people with chronic back pain may have lower proprioceptive acuity, with disruptions in the perceived size and alignment of body parts.
  • Screening tool - Orebro Musculoskeletal Pain Screening (OMPSQ) and the STarTBack tool
  • One of the most well-known is a randomized controlled trial(RCT) involving 2,534 US postal workers that demonstrated no reduction in the incidence of work-related low back pain with education in safe work practices and ergonomic redesign of the workplace.
  • The only effective intervention in this study was exercise, or exercise in combination with education, the latter of which reduced the risk of an episode of low back pain by 45%.
  • A treatment option for individuals with low back pain is a risk stratification approach.
  • In individuals with low risk who have no specific spinal pathology, clinical guidelines for the management of nonspecific low back pain in primary care recommend advising the patient to return to work as soon as possible, in addition to self-managed methods of pain relief and education about the causes and possible self-management of the pain
  • As part of the management of high-risk patients, one approach has been to offer a psychologically informed prevention programme as an adjunct to medical care that includes reassurance that the condition is not harmful and education about the importance of being active.
  • To increase the accessibility of psychologically informed interventions, these programmes have been delivered by other trained health-care professionals, such as physical therapists.
  • Electrotherapy, manual traction and belts, corsets or foot orthotics are not recommended for either acute or chronic pain.
  • No guidelines recommended surgery for the treatment of nonspecific low back pain as in the absence of a clear anatomical basis of low back pain.
  • One novel and more specific multidisciplinary treatment for non-specific low back pain is aimed at directly challenging the catastrophic misinterpretation of pain and various expectations about the relationship between physical activities and pain and/or back injury. The treatment is designed to create harm expectation violation (prediction error) by exposing patients to movements or activities that they consider harmful or that they predicted to increase pain. During treatment, these individuals’ predictions are challenged and brought in line with the incoming sensory and safety information, which provides an opportunity for learning new and more accurate predictions. Such treatment can considerably reduce levels of pain-related fear and the perceived harmfulness of physical activities and are cost-effective.
  • Social-level intervention to improve back pain health outcomes include mass media campaign to improve the understanding of low back pain in the general public, addressing the fears and expectations of health-care providers, removing compensation and disability policies that encourage disability and implementation studies that attempt to address important evidence-practice gap.