Chronic fatigue syndrome: lack of association between pain-related fear of movement and exercise capacity and disability.
OBJECTIVE
Patients who experience pain, a symptom of chronic fatigue syndrome (CFS), often exhibit kinesiophobia (irrational fear of movement). The purpose of this study was to examine whether pain-related fear of movement is associated with exercise capacity, activity limitations, or participation restrictions in patients with CFS who experience widespread pain.


METHODS
Sixty-four subjects met the inclusion criteria. All subjects fulfilled the 1994 Centers for Disease Control and Prevention case definition for CFS and experienced widespread myalgias or arthralgias. The subjects completed the Tampa Scale for Kinesiophobia-Dutch Version (TSK-DV) and the Dutch Chronic Fatigue Syndrome-Activities and Participation Questionnaire (CFS-APQ). They then performed a maximal exercise test on a bicycle ergometer. Heart rate was monitored continuously by use of an electrocardiograph. Ventilatory factors were measured through spirometry. Correlations between the TSK-DV scores and both the exercise capacity data and the CFS-APQ scores were assessed using the Spearman rank correlation coefficient. Using the Mann-Whitney U test, the TSK-DV scores were compared between subjects who performed a maximal exercise stress test and those who did not perform the test.


RESULTS
Forty-seven subjects (73.4%) attained a total score of greater than 37 on the TSK-DV, indicating high fear of movement. Neither the exercise capacity data nor the CFS-APQ scores indicated a correlation with the TSK-DV scores (n=64). Subjects who did not perform a maximal exercise capacity test had more fear of movement (median TSK-DV score=43.0, interquartile range=10.3) compared with those who did perform a maximal exercise capacity test (median TSK-DV score=38.0, interquartile range=13.2; Mann-Whitney U-test score=322.5, z=-1.974, P=.048), but the correlation analysis was unable to reveal an association between exercise capacity and kinesiophobia in either subgroup.


CONCLUSIONS
These results indicate a lack of correlation between kinesiophobia and exercise capacity, activity limitations, or participation restrictions, at least in patients with CFS who are experiencing widespread muscle or joint pain.
Nijs
Jo
J
Department of Human Physiology, Faculty of Physical Education and Physical Therapy Science, Vrije Universiteit Brussel, Brussels, Belgium. Jo.Nijs@vub.ac.be
Vanherberghen
Katrien
K
Duquet
William
W
De Meirleir
Kenny
K
D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D006233:Persons with Disabilities / Q000523:psychology; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D015673:Fatigue Syndrome, Chronic / Q000503:physiopathology / Q000523:psychology*; D005239:Fear / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D010146:Pain / Q000503:physiopathology* / Q000523:psychology*; D011795:Surveys and Questionnaires