Evaluation of a randomized controlled trial in the management of chronic lower back pain in a French automotive industry: an observational study

Abstract

Objective: To evaluate a specific workplace intervention for the management of chronic lower back pain among employees working in assembly positions in the automotive industry.

Design: Randomized controlled trial.

Setting: On site at the workplace of a French automotive manufacturer.

Participants: Subjects (N=75 volunteers) were recruited on site and randomly assigned to either an experimental group (n=37) or a control group (n=38).

Intervention: The experimental group followed a supervised 60-minute session, 3 times per week, of muscle strengthening, flexibility, and endurance training during 2 months. The control group received no direct intervention. Evaluation took place at baseline, 2 months, and 6 months.

Main outcome measures: Pain related parameters were evaluated using validated questionnaires and scales translated into French (Quebec Back Pain Disability Scale, Rolan Morris Disability Questionnaire, Dallas Pain Questionnaire, and the Tampa Scale for Kinesiophobia). Perceived pain intensity was evaluated using the numerical rating scale, and physical outcome measures were evaluated using specific indicators (flexibility, Biering-Sorensen Test, Shirado test). The multivariate analysis of variance, t test, and Wilcoxon signed-rank test were used for statistical analysis.

Results: We observed a significant beneficial effect (P<.025) for the experimental group at 2 and 6 months in pain parameters, specific flexibility, and in back functions, and a significant improvement at 6 months in the control group for the perceived pain intensity, anterior flexion, flexibility of quadriceps, and Dallas Pain Questionnaire's work recreational score. An increase in the practice of physical activity outside the workplace was noted in both groups at 2 months but persisted at 6 months for the experimental group.

Conclusions: This study reinforces the multiple health benefits of physical activity and physical therapy modalities in the workplace by assisting individuals at risk who have chronic LBP.