The Fit-for-Purpose Model: Conceptualizing and Managing Chronic Nonspecific Low Back Pain as an Information Problem

Abstract

Chronic nonspecific low back pain (LBP) is a complex and multifaceted problem. The following Perspective piece tries to help make sense of this complexity by describing a model for the development and maintenance of persistent LBP that integrates modifiable factors across the biopsychosocial spectrum. The Fit-for-Purpose model posits the view that chronic nonspecific LBP represents a state in which the person in pain holds strong and relatively intransient internal models of an immutably damaged, fragile, and unhealthy back, and information that supports these models is more available and trustworthy than information that counters them. This Perspective proposes a corresponding treatment framework for persistent pain that aims to shift internal models of a fragile, damaged, unhealthy, and unchangeable self toward the formulation of the back as healthy, strong, adaptable, and fit for purpose and to provide the system with precise and trustworthy evidence that supports this supposition while minimizing information that works against it.

Back Pain, Biopsychosocial, Chronic Pain, Predictive Processing, Rehabilitation

Introduction

Chronic nonspecific low back pain (CNSLBP) is a common and complex problem with considerable personal and societal consequences.^1–3 Prognosis is unfavorable, with recovery occurring in less than one-half of people with CNSLBP over a 1-year period.⁴ Despite a vast range of potential treatment approaches,⁵ an optimal form of care has not yet been identified. A large number of cross-sectional studies have detected countless potential targets for management across the biopsychosocial spectrum,² and it is commonly suggested that effective care needs to target multiple drivers to the clinical condition.⁶ Combining interventions from different specialties into a multimodal treatment plan has been shown to be more effective than single therapies or usual care,⁷ and multimodal care is an approach endorsed by clinical practice guidelines,⁸ though improvements in outcome remain modest. Optimization of multimodal care and further improvements in treatment outcomes may come from a richer understanding of the interaction between modifiable contributing factors that exist across the biopsychosocial spectrum and how these issues coalesce to shape the chronic pain experience and trajectory.

Here we present the Fit-for-Purpose Model (FFPM),⁹ which shares some characteristics with other approaches to understanding and managing CNSLBP but extends them by integrating cognitive and behavioral factors with modifiable neuroimmune processes. Similar to the Fear-Avoidance,^10,11 Health Belief,¹² and Common Sense¹³ models, the FFPM recognizes the importance of interactions between beliefs and behaviors in persistent pain. Also similar to those models, the FFPM has not suddenly come into being at a “single, defined moment” (eg, Leventhal et al.^13,p937) but has undergone iterative development as new discoveries have been made and new interventions tested. What sets the FFPM apart from other models is the integration of and weighting given to foundational cognitions about “how pain and healing work”; the impact on information processing, cognitions, and clinical symptoms of a plastic and adaptive neuroimmune system^14–16; and incorporation of contemporary models of learning, not least predictive processing,^17–19 into explaining the persistence of pain and disability. Finally, we have developed a coherent, staged, complex treatment approach aimed at secondary and tertiary prevention for people with CNSLBP based on our model, which is currently being tested in a clinical trial.²⁰ This Perspective Piece describes the theoretical underpinnings of the FFPM and the rationale behind each component of the complex care package. Ultimately, our aim is to provide a reasoning-based framework that will help clinicians make sense of the complexity of CNSLBP and thus provide contemporary, coherent, biopsychosocial informed management.

Theoretical Underpinnings

Noxious input from the body is likely an important part of many peoples’ pain experience, but pain does not reflect a simple readout of nociceptor activity.²¹ Current theory suggests that pain might best be considered an actively constructed experience based on multiple sources of information and reflects both conscious and non-conscious assessment that one’s body is under threat and in need of protection.^19,22

This standpoint is consistent with current concepts of perception more generally. Where once the brain was viewed as a passive processor of sensory information, it is now considered a dynamic organ of inference that makes sense of the world by actively generating hypotheses regarding the sensory inputs the individual encounters and then tests these hypotheses against sensory evidence.²³ What is perceived is the system’s final estimate of the most likely cause of sensory input derived from both prior beliefs about the body and the world and current sensory information from the body and the world.¹⁷ With regard to pain, the individual builds models of the body based on prior information from and about the body and uses these models to predict the causes of ongoing sensory information from the body, contingent on the context in which the individual is situated. Under this paradigm, pain then represents the conscious expression of a final estimate, from the integration of these information sources, that the sensory stream represents an abnormal somatic event in which there is a threat to bodily integrity and protective behavior would mitigate that threat.^18,19 In this way psychological and social factors are stitched into the fundamental neurobiological processes that underpin the emergence of a conscious experience we recognize as pain.

The FFPM leans heavily on the notion of pain emerging as the result of a dynamic interplay between stored information and information transformed by, and encoded within, sensory processing systems. Particularly, the FFPM posits the view that CNSLBP represents a state in which the individual holds relatively intransient internal models of an immutably damaged, fragile, and unhealthy back and information from the body (and the world) that supports these models is more available and trustworthy than information that counters them. The following section explores how this self-reinforcing state could arise and lead to maintenance of an ongoing pain state.

Development of CNSLBP

A Cognitive Model of an Immutably Damaged, Fragile, and Unhealthy Self Begins to Emerge

Every persistent pain state has an onset, and there are characteristics of the experiences of the individual with acute low back pain (LBP) that are particularly relevant to the FFPM. Most important are those factors that start to shape beliefs that the back is damaged, fragile, and unhealthy and that this state is resistant to change. At a societal level, it seems that LBP is viewed primarily as a result of injury to somatic structures within the back,^24,25 generally as a response to mechanical overload.²⁶ We contend, alongside others, that much of the societal messaging about back care, particularly in the work place, reinforces ideas that “backs are fragile and easily injured”²⁴ and that back pain is a particularly intransient problem.²⁷ This has implications for the individual trying to make sense of their problem based on their own internal resources but also shapes the information they would obtain from their family, their social networks, and their world more broadly. That acute LBP is commonly characterized by movement-evoked pain and often eased by rest and inactivity makes this model of pain as a marker of damage intuitively sensible as well. So both the lived experience of the person in pain and their social and informational environment contribute to the formulation of a damaged, unhealthy, and load-intolerant self.

Seeking professional help for the problem may also enhance this narrative. A number of diagnostic models for spinal pain reference tissue injury and damage as primary contributors to the pain state^28,29 and reinforce this through the provision of treatment strategies that promote unloading and volitional protection of the spine,^30–32 including messaging that protecting “your fragile back” may be required long term.³³ Furthermore, though not recommended,^34,35 imaging of the spine is still common for people receiving care for acute nonspecific LBP.³⁶ The high rate of positive imaging findings in the general population³⁷ makes it highly likely that people exposed to spinal imaging will be provided with information that appears consistent with stored impressions of damage or structural insufficiency. Moreover, explanatory models for symptoms that reference imaging findings not only reinforce damage but they also augment this impression with implied irreversibility and a pathway of progressive deterioration.³⁸

Specific clinical characteristics are also likely to drive a strong formulation of an unalterable, unhealthy self. There has been considerable research into identifying factors associated with the transition to chronicity in those with recent-onset LBP.^39–42 A number of clinical characteristics consistently identified by this research effort are likely to reinforce beliefs that the back is damaged, fragile, and unhealthy. Known indicators of poor prognosis such as high pain intensity,^43–45 symptom persistence and/or recurrence,^46,47 and the presence of other health issues^39,48–50 potentially impede recovery as they serve as reinforcers of the notion that the individual is significantly injured and unhealthy. Psychological factors that hinder recovery such as negative affect,^{39,41,51–53} pessimism about future outcome,^43,54 and health-related anxiety^51,55 are also plausible reinforcers of this account, particularly with reference to capacity for reversibility and positive change.

The majority of people experiencing an episode of acute LBP recover reasonably quickly.⁴ The FFPM contends that those who do not are those in whom social, psychological, experiential, and clinical factors shape particularly strong meta-cognitive and cognitive models of the back as being immutably damaged, fragile, and unhealthy. For these people, the process of trying to make sense of their LBP experience early in an episode leads to an understanding of the problem in which the back is appraised as being fragile and not fit for purpose and viewed as being under threat and in need of protection.

Initial Responses to the View That the Back Is Not Fit for Purpose and in Need of Protection

The model we are proposing brings 3 learning-related mechanisms into play. First, from a predictive processing perspective, as the back is moved and loaded multiple streams of sensory information from the back are generated, and, even in normal circumstances, this likely includes nociceptive input.⁵⁶ Information that is expected, based on predictive models of the response of the back to moving and loading, is given more weighting and is therefore more likely to contribute to perception.⁵⁷ In the pain-expectant individual, nociceptive input will be particularly weighted and will therefore have more influence on determining if the sensory stream accompanying movement is perceived as representing a harmful, abnormal somatic event. Critically, this increased weighting of nociceptive input is potentially accompanied by decreased weighting of non-nociceptive somatosensory information from the back, the various proprioceptive streams that are associated with back movement, and loading. Second, at a meta-cognitive level, viewing the back as easily injured and pain as a marker of tissue damage will impact the various complex and intertwined processes that are involved in making sense of what is perceived. In the individual who believes the back is not fit for purpose, pain with action is not only more likely, but pain is potentially interpreted in a more catastrophic way. The abnormal somatic event that pain signifies is not seen as minor or transient but taken to represent significant harm or damage to the body^11,58 and an experience more likely to foster distress and disablement. Third, as implicated in the fear avoidance model, concerns about the decreased capacity of the back to cope safely with movement and loading, and viewing pain as a marker of tissue damage, may drive avoidance of some tasks¹¹ and contribute to changing the way the spine is moved and controlled during other tasks, particularly the promotion of control strategies that increase rigidity^59–62 and decrease movement variability.^63–66 Actions that promote poverty of movement and inflexibility of the movement repertoire potentially change how the back is represented cortically⁶⁷ and the information available from the back with movement and loading.

These Responses Induce Functional Changes That Drive Perceptual Models of a Damaged Fragile and Unhealthy Self

Ongoing changes in action, attention, and appraisal of sensory information have potential functional consequences for the back and brain of people in pain. The negative effects of inactivity and unloading on the musculoskeletal system are well documented^68,69 and are recognized as important contributors to ongoing pain in approaches such as the fear-avoidance model.¹¹ More recently, substantial evidence has also emerged highlighting significant changes within the central nervous system in people with persistent pain. Multiple studies have documented neurochemical,⁷⁰ morphological,^16,71 and organisational^14,16,71,72 changes in the brains of people with CNSLBP, and many of these changes are evident in networks involved in attention, sensory processing, and motor planning and function.⁷³

Functional changes effecting the back and brain may impact the person with LBP in a number of ways. The factors that we think are most important in maintaining the chronic pain state and that are supported by the current literature are (1) changes in musculoskeletal health such that the back is less fit and load tolerant,^74–76 (2) increased efficiency within nociceptive networks such that there is augmentation of noxious information from the back,^77,78 (3) decreased efficiency within proprioceptive and tactile networks such that there is diminution of non-noxious somatosensory information,^79–88 and (4) disruption of brain grounded sensory and motor neural representations of the back.^67,89–95

Disruption of neurally encoded representations of the back and diminution of non-noxious somatosensory information from the back will degrade motor control of the back and likely impacts self-perception of the back such that the back starts to feel foreign, peculiar, disconnected, and unfit. Qualitative investigations support this, noting that people with LBP perceive the back as fragile and vulnerable^25,27,96 and feel a sense of alienation and rejection of the back.^97–99 When quantitatively evaluated, people with LBP represent the back differently when asked to draw how the back feels to them^100,101 and endorse questionnaire items associated with altered perceptual awareness of the back.^101–104

Emerging Perceptual Models Reinforce Cognitive Models of a Damaged Fragile and Unhealthy Self

Central to our approach is the potential for self-sustaining interactions between cognitive models, or how we think about the body in pain, and perceptual models, how the body in pain feels to the individual. A body initially conceptualized as damaged, fragile, and unhealthy increasingly feels damaged, fragile, and unhealthy. The view that the back is not fit for purpose and in need of protection is thus reinforced by information from the back, and we contend that this state can become somewhat self-sustaining. The back is more strongly conceptualized as vulnerable and damaged and the associated behavioral responses further facilitated as the back deconditions, spinal motor control is degraded, self-perception is disrupted, and information that supports the supposition of a damaged, fragile, and unhealthy self is facilitated and more strongly weighted while information that counters this becomes less available and considered less trustworthy (see Fig. 1).

Figure 1

The Fit-For-Purpose Model (FFPM) of chronic non-specific low back pain (CNSLBP).

Relevance of the FFPM to Treatment of People With CNSLBP

The FFPM not only provides a novel perspective to help patients and clinicians understand CNSLBP, it also offers a framework to guide treatment and help integrate various common and contemporary practices into a coherent, graded, rehabilitation framework. Management strategies aligned with the FFPM aim to shift meta-cognitive, cognitive, and bodily related internal models that are consistent with a fragile, damaged, unhealthy, and unchangeable self toward the formulation of the back as healthy, strong, fit for purpose, and able to adaptively respond to progressive movement and loading. Information sources from the body as well as information sources external to the person can be used to drive change. A coherent treatment approach that aims to foster fitness for purpose can be organized according to 4 therapeutic targets that seek to help the person understand it is safe and helpful to move, refine neural representations so the back feels safe to move, load the back to promote positive tissue adaptations, and allow the person the experience safety with movement and consolidate safety under load through targeted self-management strategies.

Understand It Is Safe and Helpful to Move

To foster fitness for purpose, we contend that it is important that people with CNSLBP are provided with a less threatening and more hopeful understanding of their problem and a conceptualization of the drivers to the condition that make explicit both the safety and value of movement and loading. This may encompass the benefits that movement and activity impart on the health and load tolerance of the musculoskeletal system and the dynamic sensitivity of the body’s protective systems as well as the opportunity that movement and loading provide for learning about the back, exploring its capabilities, and influencing how it is represented cortically. Pain science education, which accommodates multiple “ways of knowing” and multiple types of knowledge,¹⁰⁵ is a key intervention in promoting this understanding. This type of education emerged 2 decades ago in response to the failure of conventional back pain education and cognitive therapies to impact problematic and change-resistant conceptualizations of a damaged, fragile, and unhealthy self.^22,106,107 Modern pain science education is based primarily on a constructivist model¹⁰⁸ and encompasses a wide range of educational interventions aimed to improve an individual’s understanding of “how pain works,” including the distinction between nociception and pain and the clinical implications of this distinction; the dynamic sensitivity of nociceptors and other components of a wider “pain system”; the multifactorial processes that underpin the experience of pain and its persistence; and the ever-present tendency of biological systems to adapt to the demands placed on them, a concept recently coined as “bioplasticity.”^109,110

A central objective of pain science education is to shift an individual’s conceptualization of pain from being simply a marker of tissue damage or disease to being a dynamic protective feeling that is influenced by multiple, largely reversible factors from across the biopsychosocial spectrum that vary across temporal scales ranging from moments to years.²² Pain science education has both generic learning objectives (eg, Moseley and Butler¹⁰⁵) and learning objectives tailored to the individual. Individual learning objectives reflect specific misconceptions about the condition and individual factors that might shape the view that the back is not fit for purpose. Generic learning objectives, or “target concepts,”¹⁰⁵ are based on contemporary pain science and consumer perspectives on recovery (eg, Leake et al¹¹¹), so they change over time as new discoveries are made.¹¹² Pain science education is foundational to our intervention because of the imperative for the individual to have the required procedural and conditional knowledge¹¹³ to make optimal collaborative decisions throughout the program and beyond. Inherent in this procedural and conditional knowledge is the above-mentioned concept of bioplasticity as it applies to both positive adaptation of body tissue and the development and reversibility of “pain system hypersensitivity.” Therefore, individually specific evidence of positive adaptation of tissue—for example via available radiological reports¹¹⁴ or experiences of soft tissue healing—helps to promote deep understanding of why movement and loading are critical for full recovery. The FFPM considers scientifically based beliefs about pain, loading, movement, and functional reversibility of the biological systems that underpin pain are potentially critical if one is to engage in subsequent aspects of the treatment package.

Refine Neural Representations of the Body So the Back Feels Safe to Move

There is a growing body of evidence to show that chronic pain is associated with progressive disruptions in bodily awareness and processing of bodily information.^{104,115–117} Disruptions of bodily awareness can be distressing and provide clear evidence to the individual experiencing them that the body is not fit for purpose and contribute to degraded motor control of the spine. Clinical investigation of these disruptions relies on measures such as tactile acuity^118–120 and motor imagery performance,¹²¹ and laboratory investigation relies on brain imaging^90,122 and electromyography.¹²³ Performance in both clinical and laboratory tests seems to relate to perceptual and motor disruptions,¹⁰⁰ and neural representation training normalizes performance (eg, Moseley and Flor¹²⁰). The impact of these interventions when applied in isolation on outcomes such as pain and disability is small. However, normalizing these disruptions through neural representation training,¹²⁴ such that the body begins to feel safe to move, may serve to reinforce the central educational message that the back is safe to move and help facilitate engagement in subsequent functional activities that move and load the back. Our inclusion of neural representation training to normalize the processes that subserve “how our body feels to us” is grounded in an interpretation of embodied cognition that emphasizes that cognitive processes are influenced by the body,¹²⁵ particularly that information from the body shapes our views about the capacity of the body (eg, Zadra et al¹²⁶). With respect to training, we propose that having a back that feels safe to move encompasses both how the back feels before and during movement. The aims, then, of neural representation training are to influence bodily-related neural representations that mold the internal models of health and load tolerance of the back—factors that shape the prediction of pain with movement and loading—and to utilize strategies that seek to increase the availability and precision of ongoing non-nociceptive somatosensory information from the back while the back is moved and loaded.

To meet these aims, neural representation training should involve both precision focused sensory and motor strategies. Sensory precision training requires a combination of repeated stimuli delivered to the back along with goal-orientated attention to each stimulus using techniques such as asking the patient to describe the location of stimulation or discern different types of stimulation.¹²⁰ There is some evidence of an analgesic effect of sensory precision training in phantom limb pain¹²⁷ and in complex regional pain syndrome (CRPS).¹²⁸ In CRPS, that sensory stimulation alone has no effect¹²⁸ and that performance and analgesia are augmented by visual enhancement of touch and spatial attention¹²⁹ point to cortical adaptations underpinning the effect. Preliminary data from participants with CNSLBP suggest sensory acuity improves with sensory discrimination training,^130,131 and these improvements are associated with small reductions in pain intensity and disability.¹³² Moreover, data from other persistent pain conditions suggest that sensory precision training not only improves pain and sensory acuity but is also associated with normalization of cortical stimulus response profiles assessed using brain imaging approaches.^127,133

A possible starting point for motor precision training is motor imagery training, which typically progresses from implicit to explicit motor imagery and involves a graded engagement of neural pathways that subserve movement planning and execution without moving the physical body.^134,135 Implicit motor imagery commences with left/right judgement training in which a decision is made on whether a model viewed in an image has their back turned to the left or the right.¹³⁶ Performance on this type of task is thought to offer insight into the integrity of proprioceptive representations of the pictured body part¹³⁷ (but see Alazmi et al¹³⁸ for 1 contrasting result), so it is plausible that training targeted at improving speed and accuracy in left/right judgements might update and improve cortical representations of the back.¹³⁹ Preliminary data from people with CRPS offer some support for this idea,^140–143 and there is a strong theoretical basis for proposing that implicit motor imagery induces rapid changes in cortical processing through subthreshold inhibitory pathways between pre-motor and primary motor areas (see Moseley et al¹³⁵ for an expanded discussion). Movement observation, closely watching others move, is another approach to implicit motor imagery that has both theoretical and empirical support¹⁴⁴ and has the advantage of being able to integrate contextual and functional characteristics that are individually tailored to a patient’s fears and goals.

To further drive activation of cortical pathways involved in movement, implicit motor imagery can be progressed to explicit motor imagery, where the individual imagines performing a movement or task in the first person. This can be augmented by having the individual simultaneously observe and mentally embody videos of people performing tasks of increasing complexity and personal relevance. Clinical trials in CRPS and phantom limb pain patients demonstrate the importance of the order of components (implicit followed by explicit) in progressive motor imagery training¹⁴⁵ as well as possible clinical benefits.¹³⁴

Progression from pre-movement strategies to movement of the physical body aims to further impact on cortical representations of the back and facilitate the availability and trustworthiness of non-noxious somatosensory information associated with back movement. Exercises that focus on mindful body mastery, such as learning how to perform precise and localized movements of the lumbar spine and hips, present an opportunity to achieve this aim. For example, learning to delineate the lumbar spine from the thorax and hips and precisely demarcate movement between these adjacent areas^146,147 or learning to independently activate anatomically adjacent trunk muscles¹⁴⁸ satisfies the requirements of a task that, theoretically, should improve precision of non-nociceptive information and sharpen cortical representations. Empirical support is sparse, but preliminary data suggest that specific trunk muscle training may shift motor cortex processing in people with back pain.¹⁴⁹ Making goal attainment contingent on attention to specific movement characteristics, which will increase the weighting given to non-nociceptive data and improve the precision of cortical processing of that data, may be an important element of such approaches. Relevant here are the many common movement strategies employed by clinicians in the treatment of LBP. For example, performing a “hip stretch” could be reframed as a useful way of learning to delineate movement in the hip from movement in the back. Movement in this context, both active and passive, is seen not as a way of modifying tissue mechanics but as a way of sampling information from the body, learning about the body, updating internal models of the body, and manipulating the weighting given to sensory inputs within the context of potentially powerful cues of safety and health.

Load the Back to Promote Positive Tissue Adaptation and Experience Safety With Movement

As stated earlier, the experience of pain with movement is a very valid reason for concluding that the back is damaged, fragile, and unhealthy, and it is important to provide information to counter this view. Once the person understands that it is safe to move, observes both the disruption in somatosensory and motor processing and the resolution of these disruptions with training, and potentially starts to feel safe to move, then the treatment program can progress to functional movement training and loading. Here, the objectives are to (1) load the body and thus trigger positive adaptation towards greater load-bearing capacity of the tissues; and (2) through skilled movement coaching, provide movement and loading experiences that involve less pain than predicted and thus update internal models associated with how fit for purpose the back is. Experiencing that the back is safe to move and load builds on exposure based approaches to managing CNSLBP informed by the fear-avoidance model^150–154 such that task selection is a shared decision-making process based on the person’s goals and employs behavioral experiments designed to violate prior expectations of the effect of the task on the back. In addition to these concepts, we would advocate skillful movement coaching and task modification in which the therapist and patient work together to identify strategies that minimize symptom provocation with action and thereby provide clear evidence of a healthy, load-tolerant self and safety with function, as well as demonstrate the potential for reversibility of movement sensitivity.

The epistemic nature of movement is at the forefront of this type of exercise prescription with a focus on the individual learning about their body, how to move and complete functional tasks with decreased provocation, the impact of context on sensitivity, and the reversible nature of their sensitivity state–their so-called “protect by pain zone.”¹⁰⁹ We think this is best facilitated by a precision-focused and feedback-enriched approach to movement training and coaching in which participants progress from part practice to whole task practice of functionally relevant tasks while attention is directed towards non-nociceptive aspects of task performance through visual,¹⁵⁵ tactile, proprioceptive, and even auditory sources of information. Several treatment models have been proposed that seek to decrease movement sensitivity through reducing unhelpful protective behaviors such as breath holding and muscle co-activation¹⁵⁶ or provocative lumbar movement patterns such as disrupted load sharing.^157–159 These approaches provide valuable skills to help the clinician enact the ideas presented here. Strategies to consider could also extend beyond movement quality or loading patterns and seek to utilize cues from across psychological and social domains that infer safety (see, eg, “the Protectometer” tool¹⁰⁹). Emerging methods such as virtual reality-based training may also facilitate this step.^160,161

Figure 2

RESOLVE: a progressive complex care package based on the Fit-For-Purpose Model (FFPM).

Consolidate Safety Under Load

The long-term goal of treating CNSLBP according to the FFPM is resilience under the movement and loading conditions to which the individual is likely to be exposed. Thus, progression may continue to work-hardening contexts, traditional aerobic-based exercises, or general strength training according to the individual patient’s personal goals and values. That movement and loading of tissues triggers adaptations in those tissues and their functional engagement is well established,¹⁶² but there seems to be only weak relationships between peripheral musculoskeletal changes and clinical status.¹⁶³ What little evidence is available suggests that traditional physical training may benefit people with back pain by decreasing fear and increasing confidence.¹⁶⁴ Our approach would support a synergistic relationship between changes in the body and changes in beliefs. Positive adaptations within the tissues of the back may well contribute information that updates internal models toward a strong, healthy, and load-tolerant back. Simultaneously, the experience of undertaking intense physical training without significant symptom exacerbation provides strong evidence in support of this view and that the back is fit for purpose, even under large loads. That is, strength and fitness training provide countless potential opportunities to update meta-cognitive, cognitive, and proprioceptive internal models about the structural integrity and resilience of the back under given demands. This calls for expertly prescribed and appropriately dosed exercise in which priority is given to optimizing movement confidence rather than dosing regimens designed to simply optimize peripheral tissue adaptations.¹⁶⁵ In this way, the FFPM represents a clear shift from previous models that recognize only peripheral adaptations in response to training¹⁶⁶ or only meta-cognitive adaptations.¹⁵⁴ A final therapeutic target of the FFPM is empowering the individual with the understanding and skills to self-manage and maintain optimal physical and psychological health under future challenges.

Treatment Summary

Figure 2 outlines a complex care package based on the FFPM currently being tested in a large sham-controlled explanatory clinical trial (“RESOLVE”²⁰). The key aim of care is to reinforce fitness for purpose of the back by helping the individual: UNDERSTAND that it is safe and helpful to move; REFINE the neural representations of the body so the back FEELS safe to move; LOAD the back to promote positive tissue adaptation and experience safety with movement; and CONSOLIDATE the concept of safety under load through general exercise prescription and work-hardening programs orientated toward patient-derived goals. Each stage reinforces previous stages. Our, as yet untested, prediction is that optimal outcomes will be realized by treatment approaches that integrate these features in a synergistic manner. The FFPM has been the key theoretical guide to develop this complex care package, and we hope the model facilitates other health care professionals to make sense of those treatments they perceive as helpful and to implement them in synergistic ways that align with contemporary understanding of how pain and recovery work. We do not see this complex care package as a one-size-fits-all approach but an overarching blueprint for care in which there is significant scope for individualization in terms of the weighting of attention devoted to each of the steps, what is emphasized in each step, and how the aims of each step are best achieved for the individual. Note that all phases are individualized toward patient-derived fears, misconceptions, behaviors, and goals. Finally, tailoring of care should be optimized by assessing knowledge about “how pain works,”¹⁶⁷ beliefs about the fitness for purpose of the back,¹⁶⁸ back-specific body representations and awareness,¹⁰⁴ motor imagery performance,¹²¹ sensory precision,¹⁶⁹ and movement precision.¹⁴⁶ These assessments can help shape and refine care as well as be used to evaluate the process of care.¹⁷⁰

CNSLBP is a complex problem that is best understood through a biopsychosocial lens, particularly one that incorporates a contemporary understanding of the neurobiology of the pain experience. The FFPM regards CNSLBP as a problem of internal meta-cognitive, cognitive, and proprioceptive models that hold that the back is not fit for purpose. Based on this premise, we propose a theoretically justified, coherent, progressive complex care approach that targets modifiable factors to help shift internal models of a fragile, damaged, unhealthy, and unchangeable self towards the formulation of the back as healthy, strong, adaptable, and fit for purpose.

Key Points

• CNSLBP represents a dynamic interplay between beliefs about the body in pain, neural representations that impact on how the painful area feels and moves, the information available as the back is moved and loaded, and the capacity of the musculoskeletal system to tolerate load.

• Multimodal care for the person with back pain should seek to foster fitness for purpose by helping the person reconceptualize pain so they understand it is safe and helpful to move, targeting neural representations so the back feels safe to move, employing graded movement coaching to promote positive tissue adaptations and the experience of safety with movement and consolidate these through targeted self-management.

Author Contributions

Concept/idea/research design: B.M. Wand, A.G. Cashin, J.H. McAuley, M.K. Bagg, G.L. Moseley

Writing: B.M. Wand, A.G. Cashin, J.H. McAuley, M.K. Bagg, G.L. Moseley

Project management: B.M. Wand, A.G. Cashin

Consultation (including review of manuscript before submitting): B.M. Wand, M.K. Bagg, G.M. Orange, G.L. Moseley

Acknowledgments

The authors thank Dr Neil O’Connell from Brunel University for his comments on the manuscript and Associate Professor William Gibson and Dr Mervyn Travers from the University of Notre Dame Australia for their contribution and insightful observations on predictive processing and pain.

Funding

No specific grant was received for this study from any funding agency in the public, commercial, or not-for-profit sectors.

Disclosures

The authors completed the ICMJE Form for Disclosure of Potential Conflicts of Interest and reported no conflicts of interest.

B.M. Wand has received fees to speak about pain neuroscience and low back pain rehabilitation and is an investigator on the RESOLVE trial, which was funded by the National Health and Medical Research Council (NHMRC) of Australia, ID1087045. A.G. Cashin was supported by the University of New South Wales Prince of Wales Clinical School Postgraduate Research Scholarship and a NeuRA PhD Candidature Supplementary Scholarship. M.K. Bagg was supported by a NeuRA PhD Candidature Scholarship and was supported during this work by an Australian Research Training Program Scholarship and a UNSW Research Excellence Award. M.K. Bagg received conference travel support from the Chiropractor’s Association of Australia to speak about pain neuroscience and rehabilitation and Memorial University of Newfoundland to speak about engagement with research evidence. J.H. McAuley is supported by a Leadership Investigator Grant from the NHMRC of Australia; has received other research funding from the Australian Commonwealth National Health and Medical Research Council (NHMRC) and the Australian Medical Research Future Fund (MRFF); and is an investigator on the RESOLVE trial. G.L. Moseley is supported by a Leadership Investigator grant from the NHMRC of Australia (ID 1178444), has received other research funding from NHMRC, the Australian Medical Research Future Fund (MRFF), and is an investigator on the RESOLVE trial (NHMRC ID1087045), other Australian and overseas governments, and not for profit agencies. G.L. Moseley also has received support from Reality Health; ConnectHealth UK; Seqirus; Kaiser Permanente; Workers’ Compensation Boards in Australia, Europe, and North America; AIA Australia; the International Olympic Committee; Western Australia Cricket Association; Arsenal Football Club; Brighton and Hove Albion Football Club; and Melbourne Football Club. Professional and scientific bodies have reimbursed G.L. Moseley for travel costs related to presentation of research on pain at scientific conferences/symposia. G.L. Moseley has received speaker fees for lectures on pain and rehabilitation and receives book royalties from NOIgroup Publications and Dancing Giraffe Press, including key texts involved in the education component of the FFPM.