Effect of Training Supervision on Effectiveness of Strength Training for Reducing Neck/Shoulder Pain and Headache in Office Workers: Cluster Randomized Controlled Trial

OBJECTIVE To investigate the effect of workplace neck/shoulder strength training with and without regular supervision on neck/shoulder pain and headache among office workers. METHOD A 20-week cluster randomized controlled trial among 351 office workers was randomized into three groups: two training groups with the same total amount of planned exercises three times per week (1) with supervision (3WS) throughout the intervention period, (2) with minimal supervision (3MS) only initially, and (3) a reference group (REF). Main outcome is self-reported pain intensity in neck and shoulder (scale 0-9) and headache (scale 0-10). RESULTS Intention-to-treat analyses showed a significant decrease in neck pain intensity the last 7 days in 3MS compared with REF: -0.5 ± 0.2 (P < 0.02) and a tendency for 3WS versus REF: -0.4 ± 0.2 (P < 0.07). Intensity of headache the last month decreased in both training groups: 3WS versus REF: -1.1 ± 0.2 (P < 0.001) and 3MS versus REF: -1.1 ± 0.2 (P < 0.001). Additionally, days of headache decreased 1.0 ± 0.5 in 3WS and 1.3 ± 0.5 in 3MS versus REF. There were no differences between the two training groups for any of the variables. CONCLUSION Neck/shoulder training at the workplace reduced neck pain and headache among office workers independently of the extent of supervision. This finding has important practical implications for future workplace interventions.