Open AccessEffect of Two Contrasting Interventions on Upper Limb Chronic Pain and Disability: A Randomized Controlled Trial
Author(s) -
Emil Sundstrup,
Markus Due Jakobsen,
Christoffer H Andersen,
Kenneth Jay,
Roger Persson,
Per Aagaard,
Lars L. Andersen
Publication year - 2014
Publication title -
pain physician
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.31
H-Index - 99
eISSN - 2150-1149
pISSN - 1533-3159
DOI - 10.36076/ppj.2014/17/145
Subject(s) - medicine , physical therapy , blinding , isometric exercise , randomized controlled trial , forearm , wrist , dash , physical medicine and rehabilitation , psychological intervention , confidence interval , upper limb , chronic pain , elbow , surgery , nursing , computer science , operating system
Background: Chronic pain and disability of the arm, shoulder, and hand severely affect labormarket participation. Ergonomic training and education is the default strategy to reduce physicalexposure and thereby prevent aggravation of pain. An alternative strategy could be to increasephysical capacity of the worker by physical conditioning.Objectives: To investigate the effect of 2 contrasting interventions, conventional ergonomictraining (usual care) versus resistance training, on pain and disability in individuals with upper limbchronic pain exposed to highly repetitive and forceful manual work.Study Design: Examiner-blinded, parallel-group randomized controlled trial with allocationconcealment.Setting: Slaughterhouses located in Denmark, Europe.Methods: Sixty-six adults with chronic pain in the shoulder, elbow/forearm, or hand/wrist andwork disability were randomly allocated to 10 weeks of specific resistance training for the shoulder,arm, and hand muscles for 3 x 10 minutes per week, or ergonomic training and education (usualcare control group). Pain intensity (average of shoulder, arm, and hand, scale 0 – 10) was theprimary outcome, and disability (Work module of DASH questionnaire) as well as isometric shoulderand wrist muscle strength were secondary outcomes.Results: Pain intensity, disability, and muscle strength improved more following resistance trainingthan usual care (P < 0.001, P = 0.05, P < 0.0001, respectively). Pain intensity decreased by 1.5points (95% confidence interval -2.0 to -0.9) following resistance training compared with usualcare, corresponding to an effect size of 0.91 (Cohen’s d).Limitations: Blinding of participants is not possible in behavioral interventions. However, atbaseline outcome expectations of the 2 interventions were similar.Conclusion: Resistance training at the workplace results in clinical relevant improvements inpain, disability, and muscle strength in adults with upper limb chronic pain exposed to highlyrepetitive and forceful manual work.Trial registration: NCT01671267.Key words: Musculoskeletal pain, workability, shoulder pain, elbow pain, tennis elbow, wristpain