Why Fear of Movement Haunts Patients with Axial Spondyloarthritis
A simple stretch can feel like a high-stakes gamble for those living with chronic inflammatory pain.
When you live with a chronic inflammatory disease like axial spondyloarthritis (axSpA), every movement can require calculation. The decision to reach for a high shelf, to bend down to tie your shoes, or simply to twist while reversing your car isn't automatic—it's weighed against the potential for sharp pain, stiffness, or what patients call "flare-ups." This isn't just about physical limitation; it's about fear of movement itself—a psychological barrier that significantly shapes the experience of hundreds of thousands of people worldwide. Recent research reveals this fear isn't just a side effect of pain but a major contributor to disability that might be as important to treat as the disease itself.
When the Body Becomes the Enemy: Understanding Fear of Movement
Axial spondyloarthritis is a chronic inflammatory rheumatic disease that primarily affects the spine and sacroiliac joints, causing pain, stiffness, and progressive loss of mobility 5 . For many patients, however, the experience extends beyond these physical symptoms into a complex psychological landscape where movement itself becomes threatening.
This phenomenon is clinically known as fear of movement and (re)injury, or kinesiophobia 1 . It's a specific phobia where patients develop excessive, irrational fears that movement will cause reinjury, worsen their condition, or intensify their pain. This isn't simply "being careful"—it's a maladaptive coping mechanism that can persist long after acute inflammation has subsided.
The Fear-Avoidance Cycle
The psychological process follows a predictable pattern, often called the fear-avoidance model:
The Vicious Cycle of Fear and Avoidance
- Pain Experience: Movement causes pain due to inflammation
- Catastrophizing: The patient develops exaggerated negative thoughts about the pain ("This pain means I'm damaging my spine")
- Fear: Anticipation of pain creates anxiety around movement
- Avoidance: The patient avoids activities believed to cause pain
- Disability: Reduced activity leads to physical deconditioning, which actually increases pain sensitivity over time 2
This vicious cycle explains why many axSpA patients remain inactive despite understanding that prescribed exercises and movement are crucial to managing their condition 2 . The very treatments known to help—physical therapy, stretching, and regular exercise—become psychologically threatening.
The Belgian Breakthrough: Linking Fear to Disability
In 2018, a landmark study published in The Journal of Rheumatology provided compelling evidence for the role fear plays in axSpA disability 1 4 . Researchers at University Hospitals Leuven conducted an observational study to determine whether fear of movement beliefs actually influence activity limitations and mediate the relationship between pain severity and disability.
How the Study Worked
The research team recruited 173 patients with diagnosed axSpA and collected comprehensive data through clinical assessments and validated questionnaires 1 :
Study Measurements
- Pain and Disease Activity: Measured using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI)
- Fear of Movement: Assessed with the Tampa Scale for Kinesiophobia 11-item version (TSK-11)
- Activity Limitations: Evaluated using the Bath Ankylosing Spondylitis Functional Index (BASFI)
- Spinal Mobility: Measured with the Bath Ankylosing Spondylitis Metrology Index (BASMI)
- Inflammation: Tracked through C-reactive protein levels and physician assessments
TSK-11 Assessment
The TSK-11 questionnaire specifically probed patients' fearful beliefs with statements like:
- "I'm afraid that I might injure myself if I exercise"
- "Pain always means I have injured my body" 2
Patients indicated their agreement on a four-point scale, providing researchers with a quantifiable measure of their fear levels.
What the Research Revealed
The findings were striking. The researchers discovered that fear of movement wasn't just correlated with disability—it was an independent determinant of activity limitations 1 . Even when accounting for traditional medical factors like disease activity, inflammation levels, and spinal mobility, fear of movement consistently emerged as a significant contributor to patients' functional limitations.
Statistical analysis revealed that fear of movement partially mediated the relationship between pain and disability 1 . This means that pain leads to fear, which in turn leads to greater disability—not just that pain directly causes disability.
Table 1: Determinants of Activity Limitations in Axial Spondyloarthritis
| Factor | Influence on Disability | Statistical Significance |
|---|---|---|
| Spinal Mobility (BASMI) | Strongest determinant | β range 0.441 to 0.537 |
| Disease Activity | Major contributor | β range 0.243 to 0.571 |
| Fear of Movement (TSK-11) | Significant independent contributor | β range 0.155 to 0.321 |
| Pain Severity | Partially operates through fear | Mediated effect |
The research team concluded that the TSK-11 is "a promising and valid tool to assess fearful beliefs in relation to activity limitations in axSpA" and suggested that "fear of movement and (re)injury beliefs may represent a novel treatment target in axSpA" 1 .
Beyond Belgium: The Expanding Evidence Base
Since the 2018 Belgian study, additional research has strengthened the connection between psychology and physical function in axSpA.
A 2024 UK study confirmed that fear of movement mediates the relationship between pain catastrophizing (the tendency to magnify the threat of pain) and physical function 2 . This study introduced another important psychological factor: competence frustration—the feeling of failure or helplessness patients experience when they want to be active but fear causing pain or damage 2 .
Table 2: Psychological Factors Affecting Physical Function in AxSpA
| Psychological Factor | Definition | Impact on Patients |
|---|---|---|
| Fear of Movement | Excessive fear that movement will cause pain or reinjury | Leads to activity avoidance despite medical benefits of exercise |
| Pain Catastrophizing | Tendency to magnify, ruminate on, and feel helpless about pain | Increases perception of disability and psychological distress |
| Competence Frustration | Feelings of failure or helplessness regarding physical activities | Reduces motivation for activity participation and adherence |
Most recently, a 2025 study found significant associations between perceived pain, pain catastrophizing, and fear-avoidance beliefs with both disease activity and functional indices 5 . The interaction between perceived pain and fear-avoidance beliefs explained over 52% of the variance in disease activity scores, highlighting the powerful role psychology plays in this physical disease 5 .
A New Treatment Approach: Addressing the Mind to Heal the Body
The growing evidence for fear of movement as a driver of disability has profound implications for how axSpA should be treated. Traditionally, management has focused heavily on pharmacological approaches to reduce inflammation. While these remain essential, the research suggests they're incomplete.
"Identifying modifiable factors that contribute to disease outcomes such as physical function can improve the care and quality of life for people living with a disease currently without a cure," noted the authors of the 2024 UK study 2 .
Modern axSpA treatment requires a biopsychosocial approach that addresses not just biological factors but psychological and social ones as well 5 8 . This might include:
Cognitive Behavioral Therapy
To reframe catastrophic thinking about pain
Graded Exposure Therapy
To gradually reintroduce feared movements in a controlled manner
Mindfulness-Based Stress Reduction
To change the relationship to pain sensations
Pain Neuroscience Education
To help patients understand the difference between hurt and harm
Rheumatologists are increasingly recognizing that optimal management requires "a combination of treatment modalities (e.g., drugs, education, physiotherapy, cognitive–behavioral therapy, and exercise) that address both clinical and psychosocial factors" 5 .
The Scientist's Toolkit: Measuring Fear in AxSpA Research
To understand how researchers quantify these psychological factors, here are the key assessment tools used in the studies:
Table 3: Essential Research Tools for Assessing Psychological Factors in AxSpA
| Tool Name | What It Measures | How It Works |
|---|---|---|
| Tampa Scale for Kinesiophobia (TSK-11) | Fear of movement and (re)injury | 11-item questionnaire rated on a 4-point scale assessing beliefs about exercise and injury |
| Pain Catastrophizing Scale (PCS) | Exaggerated negative mental response to pain | 13-item instrument measuring magnification, rumination, and helplessness related to pain |
| Bath Ankylosing Spondylitis Functional Index (BASFI) | Patient-reported physical function | 10-item scale rating difficulty performing daily activities on a 0-10 scale |
| BASDAI Pain Items | Pain severity specific to axSpA | Two items from the Bath Ankylosing Spondylitis Disease Activity Index measuring spinal and peripheral joint pain |
Conclusion: Beyond Inflammation—A More Complete Picture of Care
The recognition that fear of movement significantly contributes to disability in axial spondyloarthritis represents a paradigm shift in how we understand this complex condition. Patients aren't just struggling with inflamed joints; they're navigating a psychological landscape where their own body can feel like a source of threat.
Key Insight
This research offers hope—by addressing these fear and avoidance patterns through targeted psychological interventions, clinicians can help break the cycle of disability.
Future Direction
The future of axSpA management lies in integrating these approaches with traditional medical treatments, offering patients not just reduced inflammation but restored ability to move freely and live fully without fear.
As the Belgian researchers concluded, future research applying the Tampa Scale for Kinesiophobia may reveal fear of movement as "a novel treatment target in axSpA" 1 —potentially opening new avenues for improving quality of life for those living with this challenging condition.