It’s well known for most health professionals who regularly treat patients with back pain that often patients are afraid of moving because they believe that movement will cause further pain and injury. This fear of movement, and belief that physical activities will cause (re)injury, is the central concept of the well-known Fear-Avoidance Model. According to this theoretical model, those patients with higher levels of fear of movement are more likely to develop avoidance behaviour, eventually leading to more disability and physical deconditioning (likely due to inactivity or disuse).
Our research group in a recently published paper  in Archives of Physical Medicine and Rehabilitation was interested in testing two assumptions related to the Fear Avoidance Model. The assumptions tested were whether higher fear of movement is associated with higher levels of disability (first assumption) and lower physical activity levels (second assumption). Although a great amount of research has been dedicated to test the association between fear of movement and disability, very few studies have attempted to investigate the association between fear of movement and physical activity levels. Evidence from several cross-sectional studies supports the association between fear of movement and disability but it is less clear between fear of movement and deconditioning. We noticed that, in addition to a lack of studies investigating this issue, possible explanations for the conflicting evidence in this area are the use of different measures of physical activity levels, with studies using objective measures of physical activity and another study using self-reported measure. In our study, we were particularly interested in testing the influence of both subjective and objective physical activity assessment methods when investigating the association between fear of movement and physical activity levels.
For this cross-sectional study, we analysed data from 119 patients with chronic low back pain. We used the Tampa Scale of Kinesiophobia and the Roland Morris Disability Questionnaire to respectively measure the patients level of fear of movement and disability. Physical activity levels were measured subjectively with the Baecke Physical Activity Questionnaire and objectively with an accelerometer. The measures derived from the accelerometer include counts per minute, time spent in moderate-to-vigorous and light physical activity per day, number of steps per day, and number of 10-minute bouts of moderate-to-vigorous physical activity per day.
What did we find? Our results support the Fear Avoidance Model’s assumption that higher fear of movement is associated with more disability but could not confirm the assumption linking fear of movement with inactivity. In addition, our analyses revealed that regardless of the physical activity assessment method, patients reporting higher fear of movement did not show lower levels of physical activity.
According to the Fear-Avoidance Model, we would expect that patients with higher levels of fear of movement would be consequently more disabled and less active. However, our findings showed that what happens in practice is different from what’s predicted in theory. Disability and physical activity are two constructs with important conceptual differences. Disability is often measured by questionnaires in which patients are asked to identify functional activities affected by their low back pain, including a range of spine-related functions such as twisting, bending over and sitting. Whereas subjective and objective physical activity assessment methods provide global measure of the patient’s level of physical activity. This conceptual difference suggests that patients having higher fear of movement would avoid spine-related functions, such as those tasks described in the Roland Morris Disability Questionnaire, but would remain physically active during their daily routine.
Although it seems intuitive to think that pain-related fear leads to inactivity, the available evidence is still inconclusive. Critics to the Fear-Avoidance Model say that the cyclical pathway in the fear-avoidance model might be too simplistic to understand how its components interact with each other. There is evidence to suggest a cumulative negative effect of different elevated psychosocial factors, that is fear of movement together with depression and catastrophizing, on long-term levels of pain and work disability [2,3]. There has also been a proposed alternative model  suggesting that in addition to the fear-avoidance response, there is potentially another opposite pathway leading to the development and maintenance of chronic pain. In this alternate pathway, patients develop endurance-related responses, including physical overuse or overload instead of physical disuse as the main mediators. Futures studies testing new models of behaviour are still warranted.
About Rafael Zambelli Pinto
Dr Rafael Zambelli Pinto is a Brazilian physiotherapist who travelled all the way to Australia for his PhD. Rafael completed his PhD in mid-2013 at The George Institute of Global Health in Sydney. Soon after that he joined the Pain Management Research Institute where he stayed for more than a year. He found a home back in Brazil as a lecturer in the physiotherapy department at the São Paulo State University where he keeps his research alive. Rafael can be contact at: email@example.com
 Carvalho et al. Fear of Movement Is Not Associated With Objective and Subjective Physical Activity Levels in Chronic Nonspecific Low Back Pain. Arch Phys Med Rehabil 2017;98:96-104.
 Westman et al. Fear-avoidance beliefs, catastrophizing, and distress: a longitudinal subgroup analysis on patients with musculoskeletal pain. Clin J Pain 2011;27:567-77.
 Wideman TH, Sullivan MJ. Development of a cumulative psychosocial factor index for problematic recovery following work-related musculoskeletal injuries. Phys Ther 2012;92:58-68.
Hasenbring MI, Verbunt JA. Fear-avoidance and endurance-related responses to pain: new models of behavior and their consequences for clinical practice. Clin J Pain 2010;26:747-53.
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