Joint analysis of spectrum and amplitude (JASA) of electromyograms applied for the indication of muscular fatigue in carpet weaving

Abstract Background Hand carpet weaving requires prolonged static and repetitive tasks in a stationary and constrained postures, thus there is a high prevalence of muscle pain and fatigue and musculoskeletal disorders among carpet weavers.Methods This study aimed to determining the muscle fatigue in carpet weaving tasks by Joint Analysis of Spectral and amplitude (JASA (method. Two typical carpet weaving workstations were simulated in laboratory, and 12 female carpet weavers participated in this study. Electromyography (EMG) signals were recorded during work in bilateral upper trapezius and bilateral middle deltoid. The root mean square (RMS) and median frequency (MF) values were extracted from the raw EMG signal and used to estimate muscle load and fatigue. Joint analysis of spectral and amplitude (JASA (was performed for estimating the muscle fatigue.Results Result showed that in three out of four tested muscles, muscle fatigue and force decrease in workstation B were higher than those in workstation A.Conclusion In comparison to the simultaneous analysis of amplitude and spectral parameters in JASA method, it seems that the results are more reliable than the separate analysis of spectral and amplitude parameters. However further studies on other involved muscles in carpet weaving tasks were recommended.