Shoulder girdle muscle activity and fatigue in traditional and improved design carpet weaving workstations

Work-related musculoskeletal disorders in the neck and shoulder regions are common among carpet weavers.
Working for prolonged hours in a static and awkward posture could result in an increased muscle activity and may lead to
musculoskeletal disorders. Ergonomic workstation improvements can reduce muscle fatigue and the risk of musculoskeletal
disorders. Material and Methods: The aim of this study is to assess and to compare upper trapezius and middle deltoid
muscle activity in 2 traditional and improved design carpet weaving workstations. These 2 workstations were simulated in
a laboratory and 12 women carpet weavers worked for 3 h. 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 calculated and used to assess muscle load and fatigue. Repeated measure ANOVA was performed to assess the effect
of independent variables on muscular activity and fatigue. The participants were asked to report shoulder region fatigue on
the Borg’s Category-Ratio scale (Borg CR-10). Results: Root mean square values in workstation A are significantly higher
than in workstation B. Furthermore, EMG amplitude was higher in bilateral trapezius than in bilateral deltoid. However,
muscle fatigue was not observed in any of the workstations. Conclusions: The results of the study revealed that muscle load
in a traditional workstation was high, but fatigue was not observed. Further studies investigating other muscles involved in
carpet weaving tasks are recommended.