Rehabilitation of neck-shoulder pain in women industrial workers: A randomized trial comparing isometric shoulder endurance training with isometric shoulder strength training

Objectives: To study whether isometric shoulder endurance was more advantag eous than isometric shoulder strength training in reducing pain and perceiv ed exertion and to increase shoulder function through improved muscle endur ance and strength. Design: Randomized trial. Setting: Three occupational health care centers. Participants: Women industrial workers with nonspecific neck-shoulder pain. The International Classification of Diseases, 10th Revision (ICD-10) diagn osis was "cervicobrachial syndrome" (M53.1). Thirty-eight patients complete d the isometric shoulder endurance training and 31 patients completed the i sometric shoulder strength training. Intervention: Twelve weeks of training. Main Outcome Measures: Self-reported pain and rating of perceived exertion (RPE), arm motion performance test, shoulder muscle strength, shoulder musc le endurance, and shoulder functional tests, as well as follow-up after sup ervised training had ended. Results: The isometric shoulder strength training resulted in an almost one -scale step decrease in RPE at work and a 5% to 15% improvement of arm moti on performance compared with the endurance training. The isometric shoulder strength training more effectively improved left side shoulder abduction s trength (p < .026), but no major differences were found for the other stren gth measurements. The isometric shoulder endurance training was not more su ccessful than the strength training in the endurance test (p .51 to .81). Conclusions: Physical training programs for neck-shoulder pain may include isometric shoulder muscular strength exercise in addition to isometric shou lder endurance training, rather than endurance training only.