Implementation of neck/shoulder exercises for pain relief among industrial workers: a randomized controlled trial

Abstract

Background: Although leisure-time physical activity is important for health, adherence to regular exercise is challenging for many adults. The workplace may provide an optimal setting to reach a large proportion of the adult population needing regular physical exercise. This study evaluates the effect of implementing strength training at the workplace on non-specific neck and shoulder pain among industrial workers.

Methods: Cluster-randomized controlled trial involving 537 adults from occupations with high prevalence of neck and shoulder pain (industrial production units). Participants were randomized to 20 weeks of high-intensity strength training for the neck and shoulders three times a week (n = 282) or a control group receiving advice to stay physically active (n = 255). The strength training program followed principles of progressive overload and periodization. The primary outcome was changes in self-reported neck and shoulder pain intensity (scale 0-9).

Results: 85% of the participants followed the strength training program on a weekly basis. In the training group compared with the control group, neck pain intensity decreased significantly (-0.6, 95% CI -1.0 to -0.1) and shoulder pain intensity tended to decrease (-0.2, 95% CI -0.5 to 0.1, P = 0.07). For pain-cases at baseline (pain intensity > = 3) the odds ratio - in the training group compared with the control group--for being a non-case at follow-up (pain intensity < 3) was 2.0 (95% CI 1.0 to 4.2) for the neck and 3.9 (95% CI 1.7 to 9.4) for the shoulders.

Conclusion: High-intensity strength training relying on principles of progressive overload can be successfully implemented at industrial workplaces, and results in significant reductions of neck and shoulder pain.

Trial registration: NCT01071980.

Figure 1

Flow of participants throughout the intervention.

Figure 2

The five training exercises used in the present study. A) Front raise, B) lateral raise, C) reverse flies, D) shrugs, and E) wrist extension.

Figure 3

Progression of relative intensity, i.e. repetition maximum (RM), and number of sets per exercise session throughout the 20 week training period. Notice that RM was decreased, i.e. the relative intensity increased, while the number of sets was slightly increased, but in an undulating fashion, during the training period. Data points represent weekly mean values of all sets and exercises from the training diaries of the training group (n = 282).