ABSTRACT
OBJECTIVE: The Brief International Classification of Functioning, Disability and Health (ICF) Core Sets for chronic low-back pain (cLBP) have included the three body functional categories sensation of pain, muscle functions, and emotional functions. As the latter two categories represent umbrella terms, the objective of this research was to identify those clinical tests that most expediently substantiate these two categories. DESIGN: This case-control study included 32 consecutive cLBP patients and 19 nonathletic healthy controls (HC), matched in age, body mass index, and sex. All patients and HCs underwent a comprehensive standardized clinical examination, with objective muscle functions tests that measured trunk muscle strength, endurance, and postural performance. Assessment of the category emotional functions included the Symptom Checklist 90-Revised, the Beck depression inventory, the Fear-Avoidance Beliefs Questionnaire (FABQ-D), and body experience (Borg category ratio scales about exertion, tension, fear of harm, and (re-)/injury). RESULTS: Logistic regression analyses revealed back muscle endurance and somatization to explain 50% of the between-group variances. Furthermore, the variables of Sensory Organization Test (SOT) composite score and FABQ were best associated with disablement in cLBP. CONCLUSIONS: In the Brief ICF Core Set for cLBP, back muscle endurance tests best examined the category muscle functions, whereas somatization best examined that of emotional functions. Furthermore, both the SOT and the FABQ would, in addition to the aforementioned tests, optimize the functional diagnostic relevance of the two ICF categories for cLBP.
