Study design: A prospective randomized clinical trial was conducted.
Objective: To evaluate the long-term effects of three training interventions on women with work-related trapezius myalgia.
Summary of background data: Studies with long-term follow-up evaluation of interventions for neck pain are scarce and usually cover fewer than 12 months.
Methods: For this study, 126 women with work-related trapezius myalgia were randomized into strength, muscular endurance, or coordination training or into a nontraining reference group. Intervention training occurred three times a week for 10 weeks. Assessment of pain intensity, pressure pain thresholds, symptom frequency, perceived health, and work and exercise habits was performed before and immediately after interventions, then at clinical examinations 8 months and 17 months after the interventions. Participation rates at these follow-up assessments were 84% and 81%. At 3 years after the interventions, a questionnaire was answered by 94% of the participants, 17 of whom were dropouts that never participated in any of the four intervention groups.
Results: All the training programs showed similar pain reducing effects immediately after the interventions. Pain reductions were maintained at follow-up evaluations, but at the 8-month follow-up assessment, there were no differences between the training groups and the reference group on any variable. At 3 years after the interventions, the intervention groups did not differ from the dropout group. Almost half (49%) of the women had persistent symptoms at the 3-year follow-up assessment.
Conclusions: The long-term effect of all the training programs was low. Pain in neck and shoulder muscles was persistent in a large proportion of the women over the 3 years.