Cross-sectional study of upper trapezius muscle activity and self-reported neck/shoulder pain.
Fethke NB; Gerr F; Anton DC; Cavanaugh JE; Cook TM
Proceedings of the Human Factors and Ergonomics Society 51st Annual Meeting, October 1-5, 2007, Baltimore, Maryland. Santa Monica, CA: Human Factors and Ergonomics Society, 2007 Oct; 51(15):962-966
The purpose of this crosssectional study was to compare the observed associations between upper trapezius muscle activity, as estimated with several summary measures obtained from surface electromyography (EMG), and selfreported neck/shoulder pain among a sample of 231 manufacturing workers. EMG methods used in this study included mean rootmeansquare amplitude, the amplitude probability distribution function (APDF), EMG gaps analysis, and clustered exposure variation analysis. The observed sevenday prevalence of neck/shoulder pain was 13.9%. Of the EMG summary measures, only the 90 th percentile of the APDF was significantly associated with symptoms, with crude and adjusted odds ratios of 2.57 (1.026.49) and 2.78 (1.077.21) per natural log unit, respectively. This study was largely inconclusive due to the similarity in the distributions of the summary measures between symptomatic and nonsymptomatic participants, and explicit measures of posture and repetition may produce stronger associations with symptoms.
Muscles; Musculoskeletal-system; Musculoskeletal-system-disorders; Muscle-function; Workers; Neck-injuries; Posture; Repetitive-work; Physiological-function; Cumulative-trauma; Cumulative-trauma-disorders
Nathan B. Fethke, Department of Occupational & Environmental Health College of Public Health The University of Iowa Iowa City, Iowa 52242
Proceedings of the Human Factors and Ergonomics Society 51st Annual Meeting, October 1-5, 2007, Baltimore, Maryland
University of Iowa - Iowa City