Effect of specific resistance training on forearm pain and work disability in industrial technicians: cluster randomised controlled trial

Objectives: To determine the effect of specific resistance training on forearm pain and work disability in industrial technicians. Design and setting: Two-armed cluster randomised controlled trial of 20 weeks performed at two industrial production units in Copenhagen, Denmark. Participants: Working-age industrial technicians both with and without pain and disability. Interventions: The training group (n = 282) performed specific resistance training for the shoulder, neck and arm muscles three times a week. The control group (n = 255) was advised to continue normal physical activity. Outcome: All participants rated forearm pain intensity (Visual Analogue Scale, 0-100 mm) once a week (primary outcome) and replied to a questionnaire on work disability (Disability of the Arm Shoulder and Hand, 0-100) at baseline and follow-up (secondary outcome). Results: Questionnaires were sent to 854 workers of which 30 (n = 282) and 27 (n = 255) clusters were randomised to training and control, respectively. Of these, 211 and 237 participants, respectively, responded to the follow-up questionnaire. Intention-to-treat analyses including both individuals with and without pain showed that from baseline to follow-up, pain intensity and work disability decreased more in the training group than in the control group (4-5 on a scale of 0-100, p<0.01-0.001). Among those with pain >30 mm Visual Analogue Scale at baseline (n = 54), the OR for complete recovery at follow-up in the training group compared with the control group was 4.6 (95% CI 1.2 to 17.9). Among those with work disability >30 at baseline (n = 113), the OR for complete recovery at follow-up in the training group compared with the control group was 6.0 (95% CI 1.8 to 19.8). Conclusion: Specific resistance training of the shoulder, neck and arm reduces forearm pain and work disability among industrial technicians.