Jo Nijs

Vrije Universiteit Brussel | VUB · Physiotherapy, Human Physiology & Anatomy (KIMA)

Even though nociceptive pathology has often long subsided, the brain of patients with chronic musculoskeletal pain has typically acquired a protective (movement-related) pain memory. Exercise therapy for patients with chronic musculoskeletal pain is often hampered by such pain memories. Here the authors explain how musculoskeletal therapists can al...

An increasing number of studies have examined how the immune system of patients with Chronic Fatigue Syndrome (CFS), or myalgic encephalomyelitis, responds to exercise. The objective of the present study was to systematically review the scientific literature addressing exercise-induced immunological changes in CFS patients compared to healthy contr...

Introduction: Central sensitization (CS) is present in a variety of chronic pain disorders, including whiplash, temporomandibular disorders, low back pain, osteoarthritis, fibromyalgia, headache, lateral epicondylalgia among others. In spite of our increased understanding of the mechanisms involved in CS pain, its treatment remains a challenging i...

Fatigue and pain are the most common side effects impacting quality of life (QoL) in cancer survivors. Recent insights have shown that perceived injustice (PI) can play a substantial role in these side effects, but research on cancer survivors is scarce. Furthermore, guidelines for recognizing clinically relevant levels of PI in cancer survivors ar...

Non-specific chronic low back pain (nCLBP) has been associated with nutrition. Yet, it is not clear how nutritional factors and nCLBP relate to one another. Therefore, the aim of the present study was to investigate differences in diet quality and dietary intake levels between nCLBP patients and healthy controls (HCs) and to explore the association...

This systematic review aimed to systematically investigate the literature on the effectiveness of exercise and physical activity programs on fatigue and sleep in people with arthritis. For that, seven databases were searched for relevant randomized controlled trials. After the searches, 36 studies investigating 2281 participants were included. Risk...

(1) Background: Noradrenaline and serotonin have modulatory roles in pain signaling and in exercise-induced hypoalgesia. Patients with chronic whiplash-associated disorders often show impaired exercise-induced hypoalgesia. Therefore, this study aimed to examine the isolated effect of activating serotonergic or noradrenergic descending pathways on h...

The brain can be organised into defined networks based on the coherent activity fluctuations between certain regions at rest when no external task or stimuli are applied. In patients with chronic pain, alterations in the way these networks act and interact become apparent, especially within the default mode network (DMN) and in the way it functiona...

Carpal tunnel syndrome (CTS) has been traditionally classified as primarily a neuropathic condition with or without pain. Precision medicine refers to an evidence-based method of grouping patients based on their susceptibility to biology, prognosis of a particular disease, or in their response to a specific treatment, and tailoring specific treatme...

(1) Background: Dysregulation in serotonergic and noradrenergic systems may be implicated in the neurobiophysiological mechanisms underlying pain-related cognitive impairment in chronic whiplash-associated disorders (CWAD). This study aimed to unravel the role of serotonergic and noradrenergic descending pathways in cognitive functioning at rest an...

Background: Perioperative education should be improved to decrease unfavourable outcomes after lumbar surgery. This trial aimed to compare effectiveness in terms of pain, quality of life, pain cognition, surgical experience, healthcare use, work resumption, and cost-effectiveness of perioperative pain neuroscience education (PPNE) vs traditional b...

Objectives: Physical exercise therapy is effective for some people with chronic nonspecific neck pain but not for others. Differences in exercise-induced pain-modulatory responses are likely driven by brain changes. We investigated structural brain differences at baseline and changes after an exercise intervention. The primary aim was to investiga...

Osteoarthritis (OA) is a leading cause of disability worldwide and clinical pain is the major symptom of OA. This clinical OA-related pain is firmly associated with symptoms of insomnia, which are reported in up to 81% of people with OA. Since understanding the association between both symptoms is critical for their appropriate management, this nar...

Sleep disturbances are one of the most frequent reported problems in people with nonspecific chronic spinal pain (nCSP) and presents an additional treatment challenge. Interventions targeting sleep problems are mainly based on subjective sleep complaints and do not take objective sleep into consideration. The aim of this cross-sectional study was t...

Background: A large proportion of people who sustain a whiplash injury will have persistent pain, disability, and participation problems. Several prognostic factors for functional recovery have been reported in the literature but these factors are often evaluated based on differing implementations in clinical practice. Additionally, physiotherapis...

Stress has been consistently linked to negative impacts on physical and mental health. More specifically, patients with chronic pain experience stress intolerance, which is an exacerbation or occurrence of symptoms in response to any type of stress. The pathophysiological mechanisms underlying this phenomenon remain unsolved. In this state-of-the-a...

Myofascial pain syndrome is featured by the presence of myofascial trigger points (TrPs). Whether TrPs are primary or secondary phenomena or if they relate to central or peripheral nervous system disorders is controversial. Referred pain, a cardinal sign of TrPs, is a central phenomenon driven by peripheral input. In 2021, the International Associa...

Background: Perceived injustice (PI) is a multidimensional appraisal cognition comprising the severity of loss consequent to injury, blame, a sense of unfairness, and/or irreparability of loss. PI gained increasing interest in pain research since it potentially contributes to the experience and burden of (chronic) pain. Objectives: This systemat...

Pain after a SARS‐CoV‐2 acute infection (post‐COVID pain) is becoming a new healthcare emergency but remains underestimated and most likely undertreated due to a lack of recognition of the phenomenon and knowledge of the underlying pain mechanisms. Evidence supporting any particular treatment approach for the management of post‐COVID pain is lackin...

Background: The clinical presentation and pain experience of patients with (sub)-acute low back pain ((S)ALBP) can strongly vary in clinical practice. However, despite growing evidence that psychological factors are associated with disability in chronic pain conditions including low back pain, studies examining the influence of psychological facto...

PurposeThis systematic review and meta-analysis aimed to determine the effectiveness of psychologically informed practice (PIP) with behavioural graded activity (BGA) compared to (1) waitlist controls (WLC), (2) other interventions (OI), (3) PIP alone or (4) BGA alone in cancer patients and survivors (CPaS).Methods PubMed, Web of Science and Embase...

Pain after cancer remains underestimated and undertreated. Precision medicine is a recent concept that refers to the ability to classify patients into subgroups that differ in their susceptibility to, biology, or prognosis of a particular disease, or in their response to a specific treatment, and thus to tailor treatment to the individual patient c...

To manage chronic pain, multidisciplinary interventions have been increasingly deployed , mostly in secondary or tertiary care settings. Evidence on the effectiveness of multidisciplinary intervention within primary care is scarce. This study examined the effectiveness of a primary care multidisciplinary treatment for chronic pain compared with tre...

This cross-sectional study explored associations between demographics, pain intensity and cognitions on the one hand and healthcare use (HCU) on the other hand in people undergoing surgery for lumbar radiculopathy. HCU during the 2 months preceding surgery was evaluated using a retrospective questionnaire. Demographics included sex, age and level o...

Background: In the pathogenesis of knee osteoarthritis (KOA), inflammatory mediators play an important role. However, the precise underlying mechanism by which regular exercise therapy (ET) exert effects on the immune system in KOA patients is unknown. Objectives: The aim of this systematic review was to investigate the basal and acute effects o...

In low back pain (LBP), primary care and secondary prevention of recurrent and persistent LBP are not always successful. Enhanced understanding of neural mechanisms of sensorimotor processing and pain modulation in patients with acute LBP is mandatory. This explorative fMRI study investigated sensorimotor processing due to mechanosensory stimulatio...

Introduction: The On&Out study is aimed at assessing the effectiveness, cost-utility and physiological underpinnings of the FIBROWALK multicomponent intervention conducted in two different settings: online (FIBRO-On) or outdoors (FIBRO-Out). Both interventions have proved to be efficacious in the short-term but there is no study assessing their com...

Background Catechol-O-methyltransferase (COMT) has been shown to influence clinical pain, descending modulation, and exercise-induced symptom worsening. COMT regulates nociceptive processing and inflammation, key pathophysiological features of Chronic Fatigue Syndrome and Fibromyalgia (CFS/FM). We aimed to determine the interactions between genetic...

Pain after an acute Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) condition (post-COVID pain) is becoming a new healthcare emergency. Precision medicine refers to an evidence-based method of grouping patients based on their diagnostic/symptom presentation and then tailoring specific t...

Background A growing body of evidence has demonstrated the importance of implementing movement-evoked pain in conventional pain assessments, with a significant role for psychological factors being suggested. Whether or not to include these factors in the assessment of movement-evoked pain has not yet been determined. Objectives The aim of this sys...

Background In healthy people and people with nonspecific chronic spinal pain (nCSP) and/or insomnia, participation in physical activity on a regular basis has several physical and psychological health benefits. However, people with chronic conditions often tend to reduce physical activity participation which can lead to deconditioning over time. Cu...

Objective The present cross-sectional study aims to unravel associations between pain intensity and cognitions versus quantitative sensory testing in people scheduled for surgery for lumbar radiculopathy. Additionally, insight will be provided in the presence of dysfunctional nociceptive processing and maladaptive pain cognitions in this population...

Background Pain experience has a multidimensional nature. Assessment and treatment recommendations for pain conditions suggest clinicians use biopsychosocial approaches to treat pain and disability. The current pain research is overwhelmingly skewed towards the study of biological and psychological factors including interventions, whereas, cultural...

Background: Currently, evidence regarding fear avoidance beliefs as potential predictors for lumbar surgery outcomes seems insufficient and strong conclusions are not yet available. Objective: This systematic review aimed to evaluate the predictive value of preoperative fear avoidance beliefs for postoperative pain intensity, functional status,...

Quality improvement is now a central tenet in physiotherapy care, and quality indicators (QIs), as measurable elements of care, have been applied to analyze and evaluate the quality of physiotherapy care over the past two decades. QIs, based on Donabedian’s model of quality of care, provide a foundation for measuring (improvements in) quality of ph...

The aim of this study was to examine associations between CS and catastrophizing, functionality, disability, illness perceptions, kinesiophobia, anxiety, and depression in people with chronic shoulder pain (SP). In this cross-sectional study, 64 patients with unilateral chronic SP completed a few questionnaires including the Central Sensitization I...

Background: Musculoskeletal (MSK) injury is one of the major causes of persistent pain. Objective: This systematic literature review explored the factors that lead to persistent pain following a MSK injury in the general population, including athletes. Methods: A primary literature search of five electronic databases was performed to identify...

Individuals who survived coronavirus disease, 2019 (COVID-19), often have symptoms of sensitization, but the extent to which these symptoms relate to serological biomarkers remains unclear. Therefore, this secondary analysis evaluated the association between serological biomarkers at hospital admission with sensitization-associated post-COVID-19 sy...

Most people who have nonspecific chronic spinal pain (nCSP) report comorbid insomnia. However, in current treatment strategies for nCSP, insomnia is usually not addressed. Considering the bidirectional interaction between pain and sleep and its underlying psychophysiological mechanisms, insomnia may increase the risk of developing adverse physical...

Objective: To investigate the association between demographic, clinical, psychological, cognitive, and health-related variables and the Central Sensitization Inventory (CSI) in previously hospitalized COVID-19 survivors exhibiting "de novo" post-COVID pain. Methods: Seventy-seven (n=77) COVID-19 survivors with "de novo" post-COVID pain completed...

We aimed to explore a path model identified using a structural equation model (SEM) which best explains the multivariate contributions of sensitization, sensitivity, and emotional variables to clinical severity in women with FMS. Pain features, the Central Sensitization Inventory (CSI), painDETECT, S-LANSS, the Hospital Anxiety and Depression Scale...

Chronic pain has a massive personal and socioeconomic impact and remains a challenge for many clinicians around the world [...]

Background: Whiplash injuries typically occur from a motor vehicle collision and lead to chronic whiplash-associated disorders (CWAD) in 20% to 50% of cases. Changes in neurotransmission, metabolism, and networks seem to play a role in the pathogenic mechanism of CWAD. Objectives: To further elucidate the functional brain alterations, a neurophy...

Objectives: Quantitative Sensory Testing (QST) is used to test somatosensory functioning in patients with low back pain (LBP) and most performed on people with chronic LBP in secondary/tertiary health care facilities. Studies using QST-testing on LBP populations in primary care are scarce. Central Sensitization Inventory (CSI) measures central sen...

Purpose The primary goal of this study was to compare the health-related quality of life (HRQoL) of people with lumbar radiculopathy to age- and sex-adjusted population norms. Additionally, it aimed to explore the associations between the HRQoL difference scores and measures related to pain cognitions, pain intensity, and endogenous nociceptive mod...

Objective: To estimate the effects of musculoskeletal rehabilitation interventions on movement-evoked pain and to explore the methods/protocols used to evaluate movement-evoked pain in adults with musculoskeletal pain. Design: Systematic review with meta-analysis. Literature search: Three electronic databases (PubMed, Web of Science, and Scopu...

Evidence for the relationship between chronic pain and nutrition is mounting, and chronic pain following cancer is gaining recognition as a significant area for improving health care in the cancer survivorship population. This review explains why nutrition should be considered to be an important component in chronic pain management in cancer surviv...

Objective Multidimensional aspects of pain have raised awareness about cognitive appraisals, such as perceived injustice (PI) and pain catastrophizing (PC). It has been demonstrated that they play an important role in patients’ pain experience. However, the mediating effect of these appraisals has not been investigated in breast cancer survivors (B...

: Physical therapists have unique education in the comprehensive biopsychosocial assessment and treatment of chronic pain and its mechanisms. Recently, physical therapists have raised awareness regarding the impact of nutrition on promoting health and managing noncommunicable diseases. Robust evidence supports the implementation of nutrition in ph...

This review discusses chronic pain, multiple modifiable lifestyle factors, such as stress, insomnia, diet, obesity, smoking, alcohol consumption and physical activity, and the relationship between these lifestyle factors and pain after cancer. Chronic pain is known to be a common consequence of cancer treatments, which considerably impacts cancer s...

Background: Chronic Whiplash Associated Disorders (CWAD) are characterized by long-lasting symptoms of neck pain occurring after an acceleration-deceleration injury. Central sensitization (CS) has been suggested as the possible underlying mechanism for these symptoms, and is characterized by changes in the central nervous system. Besides CS, psych...

Background Current evidence supports the use of pain neuroscience education (PNE) in several chronic pain populations. However, the effects of PNE at group level are rather small and little is known about the influence of personal factors (e.g. level of education [LoE]). Objective To examine whether the effectiveness of PNE differs in chronic spin...

Background The importance of cognitive appraisals in the effectiveness of pain coping is well established. Two key variables in these appraisal processes are pain catastrophizing (PC) and perceived injustice (PI), which are known to increase the risk of long-term disability and aggravate the pain-related distress through maladaptive behavioral resp...

Although autonomic nervous system (ANS) dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) has been proposed, conflicting evidence makes it difficult to draw firm conclusions regarding ANS activity at rest in ME/CFS patients. Although severe exercise intolerance is one of the core features of ME/CFS, little attempts have bee...

The Central Sensitization Inventory (CSI) measurement properties in patients having nonspecific, noncancer pain are well-established. However, studies examining the reliability and validity of either the CSI or the Central Sensitization Inventory short-form version (CSI-9) in breast cancer survivors (BCS) are scarce. The purpose was to evaluate con...

Chronic spinal pain, including both neck and low back pain, is a common disabling disorder in which sleep problems are frequently reported as a comorbidity. The complex processes of both sleep and chronic pain seem to have overlapping mechanisms, which may explain their often established bidirectional relationship. This systematic review aims to in...

Objective: This explorative study investigates the moderating effect of sex and baseline pain characteristics on the effectiveness of preoperative pain neuroscience education (PNE) plus knee joint mobilization versus biomedical education plus knee joint mobilization in patients who have knee osteoarthritis and are scheduled to undergo total knee a...

Objectives: Many people living with musculoskeletal pain conditions experience a range of negative biopsychosocial responses to physical activity, referred to as increased sensitivity to physical activity (SPA), that may undermine successful rehabilitation. This exploratory study aims to provide the first prospective analysis of the potential prog...

Amongst adults with chronic pain, overweight and obesity are highly prevalent. The association between chronic pain and overweight is driven by several explanations, including increased biomechanical load, changes in the gut microbiome, and low-grade (neuro)inflammation. Moreover, the link between overweight, obesity and chronic pain can best be co...

Background: Chronic pain is one of the most often seen, but often undertreated, sequelae in survivors of cancer. Also, this population often shows significant nutritional deficiencies, which can affect quality of life, general health status, and even risk of relapse. Given the influence of nutrition on brain plasticity and function, which in turn...

Background: The presence of pain decreases survival rates in cancer. Pain management in clinical settings is often suboptimal and secondary to other cancer-related treatments, leaving many people undertreated. Opioid use is associated with side effects and decreased survival rate in cancer patients. Hence, there is an urgent need for considering f...

Recently, the International Association for the Study of Pain (IASP) released clinical criteria and a grading system for nociplastic pain affecting the musculoskeletal system. These criteria replaced the 2014 clinical criteria for predominant central sensitization (CS) pain and accounted for clinicians' need to identify (early) and correctly classi...

Insomnia is a major problem in the chronic spinal pain (CSP) population and has a negative impact on health and well-being. While insomnia is commonly reported, underlying mechanisms explaining the relation between sleep and pain are still not fully understood. Additionally, no reviews regarding the prevention of insomnia and/or associated factors...