Editor’s note: The 2021 Global Year About Back Pain is underway, with many resources and activities planned throughout the year, including webinars. Here, we take a look back at a webinar from the 2020 Global Year for the Prevention of Pain. Stay tuned for similar webinars for the 2021 Global Year; you can submit a webinar proposal (or resource) here.
A 2020 IASP Global Year for the Prevention of Pain webinar, “Pain Prevention After Musculoskeletal Trauma,” highlighted work from four researchers on the prediction and prevention of the transition from acute to chronic musculoskeletal pain following an injury. According to the presenters, over the last 20 years, the global burden of non-musculoskeletal conditions such as infectious diseases has decreased, but the burden of musculoskeletal injuries has continued to rise. For instance, in terms of the leading causes of disability-adjusted life-years (DALYs), low back and neck pain rose from #12 in 1990 to #4 in 2013, according to the Global Burden of Disease Study 2013 (Murray et al., 2015). Research also suggests the need for improved interventions to treat those with these conditions to prevent the transition from an acute to a chronic pain state.
“We live in a world of just incredible technological innovation. Why is it, with all this great technology, we don’t seem to be improving the outcomes for people with very common and highly burdensome neck and back pain?” asked presenter David Walton, Western University, Ontario, Canada. The other presenters included James Elliott, University of Sydney, Australia; Timothy Wideman, McGill University, Montreal, Canada; and Geoffrey Bostick, University of Alberta, Canada.
During the webinar, the presenters showed how the treatment of acute and chronic musculoskeletal pain can be immensely complex. Each speaker offered their insight on patient factors that are often overlooked and which may impact the recovery of those with musculoskeletal pain. The event highlighted the need to look beyond just tissue pathology and commonly reported items such as the nature of injury associated with musculoskeletal pain, while introducing new considerations for treatment when working with people who have chronic pain.
A recording of the session, which took place August 6, 2020, is freely available here.
What about whiplash in bull riders?
Walton began by discussing subgroups of individuals who have experienced musculoskeletal traumas. These subgroups, or “trajectories to recovery,” include those who will recover quickly and uneventfully, some whose recovery will be delayed or incomplete, and finally those with little recovery and significant persistent symptoms.
“Anyone who manages people in pain probably can appreciate the statement that it would be much better to identify and perhaps prevent the genesis of chronic pain early, rather than try and treat it after it has taken hold and become quite difficult to manage,” Walton said. “Are we getting better at improving outcomes following acute musculoskeletal trauma? By and large, we are not having a tremendously good effect with many of our interventions in preventing chronic pain. We are fairly good at identifying people who are at higher risk, but we have yet to figure out how best to prevent its onset.”
To delve deeper into understanding why some people with musculoskeletal trauma transition to a chronic pain state, Walton relayed an anecdote about an experience he had during a presentation at a conference in Texas. An audience member asked if he had investigated whiplash injuries in bull riders. Whiplash-associated disorders is a term used to encapsulate multiple symptoms, often in the cervical spine (neck) region, resulting from a rapid acceleration-deceleration, something that is common in motor vehicle collisions. Being from Canada, where bull riding is not as popular as in other regions of the world, Walton had not previously looked into this topic, so he took it upon himself to explore the literature to learn more. He came across observational studies of whiplash not only in bull riders, but also in those engaging in similarly dangerous activities including demolition derby car driving. Although people taking part in these activities had a risk of cervical spine trauma similar to that seen with a car collision, few of them reported persistent whiplash symptoms.
“There’s something different about the experience of being involved with something like a road traffic collision that might predispose someone to developing widespread or long-term pain that doesn’t seem to be present in people who are selectively choosing to hop onto a bull or get into a demolition car,” Walton said.
Walton said that what is different during a trauma, such as that from a motor collision, may be the added factor of post-traumatic stress, which could trigger negative emotional and cognitive reactions including fear, anxiety, or hopelessness. All of these are stronger indicators of the development of chronic whiplash-associated neck pain than parameters specific to the motor collision itself such as the speed of the vehicle or direction of the collision.
Walton went on to describe a biopsychosocial model for chronic whiplash disorder after a cervical injury that integrates psychological and pre-existing patient factors such as the socioenvironmental context (Walton and Elliott, 2017). He described two key aspects of this model.
First, he explained how a stress response is the body’s natural reaction to trauma, and it helps tissues to heal, but sometimes this response can go awry. “In some people, that stress reaction is poorly regulated, it is maladaptive, it doesn’t have the protective effect that it should, and kicks off this genesis of ongoing pain,” he said.
Second, Walton explained how pre-existing factors such as early life adversity and stress can also influence outcomes following trauma. These are vulnerabilities or predictive factors, known as diatheses, that are specific to each individual and may include adverse childhood experiences and poor mental health. These diatheses may contribute to distress and ultimately functional interference resulting from persistent pain.
Walton ended by saying that “none of us encounter trauma in a vacuum. None of us encounter trauma in the exact same way.” He said the inclusion of predictive risk factors adds to the robustness of his integrated model for chronic whiplash disorder. But he urged caution in how these findings are interpreted to avoid labeling people with more challenging life experiences as inherently fragile or vulnerable. He stated that “these are things that we are just now starting to scratch the surface of.”
Imaging the spinal cord to understand recovery from trauma
James Elliott discussed work from his lab using computed tomography and MRI of the cervical spine after motor vehicle collision and incorporation of psychological factors into the prediction of recovery from trauma. He proposed that prediction should be based not only on cervical tissue pathology identified by imaging, but also on an interaction of psychological stress secondary to the trauma with tissue dysfunction.
In support of that approach, he pointed to a recent study he and his colleagues completed that used crash reconstruction techniques for motor vehicle collisions (Elliott et al., 2019). Here, an engineer was provided with photographs of the vehicles involved, reports from the vehicle body shop, crash reports from occupants in both vehicles, police reports, and witness accounts. Additional information in crash reconstruction includes direction of the impact, presence of head restraint, head position at the time of the collision, and preparedness for impact but, interestingly, Elliott found that none of these parameters explained recovery of those involved in the crashes. Instead, there was a strong association among self-reported neck disability, post-traumatic distress, negative affect, and uncontrolled pain three months after the collision.
Elliott further emphasized the importance of psychological factors by describing his work using computed tomography imaging of the cervical spine in people who were involved in a motor vehicle collision (Elliott et al., 2020). In those with severe disability that had not resolved at three months post-injury, a majority demonstrated more than three pathologies on their scan. Interestingly, these individuals also had higher levels of post-traumatic distress and overall pain when compared to the group whose symptoms had resolved.
Elliott next described an additional finding from CT imaging in the cervical spine region, in another of his studies (Elliott et al., 2020). In those who had poor recovery after a motor vehicle collision, CT imaging revealed that muscles deeper in the neck had reduced attenuation and resembled fatty tissue. The muscle attenuation values were highly correlated to muscle fat infiltration observed using MRI in those same individuals one week after the collision. Elliott said the fatty tissue findings in deep muscle of the neck may be unique to those who transition to chronic whiplash after a collision.
A final imaging technique Elliott is using is called magnetization transfer with high-resolution MRI, which allows for comparison and mapping of gray and white matter to examine the integrity of myelin in the cervical spinal cord. This approach has revealed differences between males and females in myelin integrity in white matter pathways in those who do not recover following whiplash trauma.
Elliott said that the imaging findings could help identify who is at risk for development of chronic whiplash symptoms such as neck pain and disability following a vehicle collision, though they are certainly not the be-all and end-all.
“I will never sell a muscle profile attenuation as the only thing you need [for predictive purposes]. There’s a lot of other things we measure as well, but maybe it is a biological contributor to the overall recovery,” he said.
Exercise is good for pain, but don’t forget it can also cause pain
Timothy Wideman offered a clinical perspective emphasizing the importance of considering the pain that can accompany exercise. He began with an overview of recent recommendations for physical activity as a way to address chronic musculoskeletal pain.
“One of the major barriers standing in the way to get the benefits [of exercise] is often pain and increasing pain,” Wideman said. He also argued that many self-report questionnaires aren’t specifically designed to assess these types of painful responses to physical activity.
As a solution to this problem, Wideman has proposed the construct of Sensitivity to Physical Activity (SPA), which encapsulates commonly used concepts in pain research including activity-related pain and movement-evoked pain. To illustrate the value of assessing SPA, he pointed to a systematic review of movement-evoked pain versus pain at rest in postsurgical clinical trials and meta-analyses (Srikandarajah and Gilron, 2011). The research found increases of 95% to 156% when comparing pain levels at rest to pain levels during physical activity following surgery in the first three days after surgery. Given the large increase in pain with activity, this may negatively impact a patient’s ability to get out of bed for their rehabilitation.
Wideman also pushed for a reframing of how functional measures are used in the clinic. He referred to the six-minute walk test, which measures the distance one can walk continuously, on a level surface, for six minutes. Clinicians often focus solely on the scores on these tests, which are generated after completion of the assessment, but Wideman said it’s also important to examine pain ratings during the test. He described the clinical reasoning often employed in situations where an individual has a poor performance on the test.
“The assumption based on our training would be that the patient is deconditioned, and by extension, the normal conclusion would be to encourage this patient to exercise,” according to Wideman. “What’s important here is when they’re encouraging them to exercise, they might be overlooking the sensitivity component. There is more of a likelihood that this patient would flare up and have a poor response to physical activity.”
Wideman’s work has shown that SPA, and not the actual distance walked during the six-minute walk test, predicts patient pain-related disability (Wideman et al., 2016). “This highlights that at the very least we could be having a bit broader picture of our patients in terms of where they are at and treatment considerations that we want to take into account,” he said.
The patient perspective
Geoffrey Bostick highlighted the perspective of people living with chronic pain. He referred back to Walton’s discussion of the ability to predict outcomes, noting that the integration and communication of these predictions in patient care have been problematic.
He discussed the use of labels and the consequences of giving labels to people with pain. While prognostic labels can assist recovery by identifying the need for targeted treatments as people recover, they may also produce stigma that adversely affects treatment, particularly in marginalized populations, such as women. For example, Bostick pointed to a study that found that healthcare providers were more likely to recommend pharmacological interventions for men in pain and psychological interventions for women in pain (Schäfer et al., 2016).
Bostick argued that this difference in suggested treatments may create stigma. In a qualitative study from Bostick that included female participants with chronic noncancer pain, he and his colleagues found that these women were less likely to recommend psychological assessment for other women in pain, citing concerns about healthcare providers not believing the person with pain and about any labels that would follow if psychological interventions were sought (Bostick et al., 2018).
Bostick then described challenges of communicating prognosis for recovery. Patients often want to know their prognosis and, ethically, clinicians are required to discuss it, but Bostick said this type of communication may not be happening enough. Adding to the complexity of prognosis communication is when a mismatch exists between the patient’s expectation about recovery and the clinician’s expectation. Bostick and his team have explored these mismatched situations in patients with neuropathic pain (Bostick et al., 2017), asking the patients to predict their treatment outcomes at six months. The researchers identified three “expectation groups” among the participants: optimistic, realistic, and pessimistic. Those in the optimistic group had lower levels of pain, disability, and psychological distress after treatment compared to those in the realistic and pessimistic groups.
“It’s important that a clinician not necessary pigeonhole a patient into a particular trajectory based on their assessment of prognosis or recovery trajectory, because we don’t want to necessarily stifle hope and optimism,” Bostick said. He added, “There’s value in maintaining that optimism or hope, even in the face of a complex or likely poor recovery trajectory.”
The presenters and their work challenge clinicians and researchers to look beyond obvious patient characteristics such as the nature of the injury. Instead, the speakers illuminated the need to further explore an individualized approach for each patient. Considering the patient as a whole, including social and psychological factors; carefully choosing the words used to communicate prognosis; using appropriate clinical decision-making to utilize and integrate advanced imaging into practice; and rethinking the evaluation of physical assessments during the course of care may all enhance treatment and be the next steps for rehabilitation professionals to take toward preventing the transition from acute to chronic musculoskeletal pain.
Andrew Post is a PhD student at the University of Iowa, Iowa City, US, and a PRF Correspondent.
Image credit: stellar001/123RF Stock Photo.