Research Article Lasting Effects of Workplace Strength Training for Neck/Shoulder/Arm Pain among Laboratory Technicians: Natural Experiment with 3-Year Follow-Up Peter Mortensen, 1 Anders I. Larsen, 1 Mette K. Zebis, 2 Mogens T. Pedersen, 3 Gisela Sjøgaard, 4 and Lars L. Andersen 5 1 Novozymes A/S, Medical Centre, 2880 Bagsværd, Denmark 2 Arthroscopic Centre Amager & Gait Analysis Laboratory, Copenhagen University Hospital, 2650 Hvidovre, Denmark 3 Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2100 Copenhagen, Denmark 4 Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, 5000 Odense, Denmark 5 National Research Centre for the Working Environment, 2100 Copenhagen, Denmark Correspondence should be addressed to Lars L. Andersen; lla@nrcwe.dk Received 22 November 2013; Revised 13 January 2014; Accepted 15 January 2014; Published 10 March 2014 Academic Editor: Nicola A. Maiuletti Copyright © 2014 Peter Mortensen et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Objectives. his study investigated long-term efects and implementation processes of workplace strength training for musculoskele- tal disorders. Methods. 333 and 140 laboratory technicians from private and public sector companies, respectively, replied to a 3-year follow-up questionnaire subsequent to a 1-year randomized controlled trial (RCT) with high-intensity strength training for prevention and treatment of neck, shoulder, and arm pain. Being a natural experiment, the two participating companies implemented and modiied the initial training program in diferent ways during the subsequent 2 years ater the RCT. Results. At 3-year follow-up the pain reduction in neck, shoulder, elbow, and wrist achieved during the irst year was largely maintained at both companies. However, the private sector company was rated signiicantly better than the public sector company in (1) training adherence, (2) training culture, that is, relatively more employees trained at the workplace and with colleagues, (3) self-reported health changes, and (4) prevention of neck and wrist pain development among initially pain-free employees. Conclusions. his natural experiment shows that strength training can be implemented successfully at diferent companies during working hours on a long-term basis with lasting efects on pain in neck, shoulder, and arm. 1. Background Musculoskeletal pain and disorders are a major public health issue with a signiicant burden on health care systems and loss of work ability and productivity [1–5]. Neck and shoulder pains are among the most common musculoskeletal disorders with individual costs ranging from minor episodes of pain to severe and chronic disability [6, 7]. Arm and hand pain are less prevalent than neck and shoulder pain but still have major impact on sickness absence [5]. Pain in the neck, shoulder, and arm is related to physical work stressors as repetitive work, forceful exertions, static muscle contractions, awkward postures, and psychosocial factors [2, 8]. Among others, laboratory technicians—known to perform repetitive and monotonous arm/hand work tasks— show a high prevalence of such pains [9, 10]. Speciic strength training reveals promising results in rehabilitation of neck and shoulder pain among oice work- ers [11–14] where even a single set of strength training to fail- ure 3 times a week provides moderate reductions of headache and neck pain [12, 15]. he rehabilitative efect of speciic strength training on pain in the neck and shoulders has also been shown among laboratory technicians, where a 20-week, 1-hour a week intervention was undertaken during working hours [16–18]. Despite these promising results efective long- term implementation of strength training at the workplace and during working hours remains challenging. Hindawi Publishing Corporation BioMed Research International Volume 2014, Article ID 845851, 14 pages http://dx.doi.org/10.1155/2014/845851