Subjective and objective assessment of neuromuscular fatigue in female painters

Abstract

The aim of this study was to evaluate subjectively and objectively neuromuscular fatigue in female painters before and after a workingday. The subjects (n=11) were female painters aged 22–60 years. The subjects completed a questionnaire and gave a subjective evaluation on muscle fatigue sensation in hands, trunk, back and lower limbs according to Borg's Category Ratio (CR-10) scale. Thereafter they performed 3-minute test of painting a wall, in the course of which the electromyographical (EMG) power spectral median frequency (MF) slope for biceps brachii, trapezius, deltoid and infraspinatus muscles was measured. The results indicated a significant change in the subjective muscle fatigue sensation in hands by 40%, lower limbs by 54% and trunk by 57% after the working day, compared to the beginning of the working day. EMG power spectral MF slope of the measured muscles did not differ significantly during the 3-minute wall coloring test before and after working day. It was concluded that subjective muscle fatigue sensation in hands, lower limbs and trunk was higher after the working day whereas it was less pronounced in the back. Muscle fatigue evaluated objectively by MF slope of EMG power spectrum from biceps brachii, trepezius, deltoid and infraspinatus muscles was not evident during the wall coloring test before and after the working day.