Predictive value of the "fear-avoidance" model on functional capacity evaluation (FCE) after orthopaedic trauma.

OBJECTIVE: Functional capacity evaluation (FCE) based on a safe maximal performance (kinesiophysical criteria), is used to evaluate abilities of a patient to accomplish work-related tasks that may help precise functional limitations. As known in chronic pain, psychosocial factors and behavioral factors have been shown to influence FCE. The influence of the "fear-avoidance" model on FCE is debated (van Abbema, 2011) and has never been studied with a full model. The goal of this study was to evaluate the influence of the fear-avoidance model on FCE performance in patients admitted for vocational rehabilitation after orthopaedic trauma.

MATERIAL/PATIENTS AND METHODS: This prospective study used low lifting maximal performance following FCE protocol (WorkWell(©)) with kinesiophysical criteria (maximal performance judged by observer) as evaluation criteria. Statistical analysis was performed with multiple regressions. These predictive variables from "fear-avoidance" model were collected with self-questionnaires during the first two days of hospitalization: catastrophism (Pain Catastrophizing Scale [PCS]); kinesiophobia (Tampa Scale for kinesiophobia [TSK]); depression (Hospital Anxiety and Depression Scale [HADS]) and perception of disability (standardization on 200 points for spinal function sort [SFS] or hand function sort [HFS]). The following confondant variables were used: age, BMI, sex, severity of trauma, pain intensity, circumstance of trauma, education, native language, professional qualification, length of work incapacity.

RESULTS: Two hundred and ninety eight patients, (male: 97.2%), mean age 41.8 years (±11.9), non French native language (57.5%), without professional qualification (57.5%) were enrolled. After developing a psychological variable grouping arithmetic means of the 3 z-scores of the fear-avoidance model (PCS, TSK, HAD-d), multiple regressions found a prognostic value of this psychological variable for low lifting (ß=-2.7, P=0.09), explaining 37.5% of the variance (R2).

DISCUSSION - CONCLUSION: Although FCE are based on a kinesiophysical approach those results suggest the importance to integrate psychological variables of the Fear-avoidance model (catastrophism, kinesiophobia and depression) in the interpretation of FCE performances.