SEMG and Postural Analysis for Biomechanical Risk Assessment in a Banknotes Printing Process

Abstract

AbstractThe purpose of this paper is to assess the biomechanical overload risk of some tasks that are typical of the printing industry, by means of surface electromyography and postural analysis software.In the first task of manual loading, muscle activation percentage duration of the Bicepses and Tricepses were similar for similar duty cycles. The Erector Spinae muscles had higher %MVC sustained for a greater percentage of the duty cycle. In the second task of aeration and transfer, Bicepses were activated for most of the duty cycle with a low %MVC between 0 and 5%. Differently, Triceps and Erector Spinae muscles had muscle activations with higher %MVC and higher percentage duration. In the third task, the muscular activity achieved the highest values in the Bicepses, while the activity of the Erector Spinae and Triceps muscles was less significant. Finally, in the fourth task, the compressive force values at the L5/S1 level found by 3DSSPP software ranged from 1072 N to 1863 N. Still at the L5/S1 level, shear forces ranged from 263 N to 310 N.In the observed conditions, the used methods found no significant biomechanical overload risk in the studied tasks. The %MVC values within the cycle were all below the threshold proposed by ACGIH. The force values at level L5/S1 estimated with 3DSSPP software were also less than the 3400 N threshold limit value proposed by NIOSH for compressive forces and less than the 700 N limit proposed for shear forces by Gallagher in his review.One of the observed activities at a faster working pace could increase the biomechanical risk. This is the case of the manual loading of the offset printing machine. In fact, the sheet board with the sheets to be loaded was positioned frontally to the printing machine loading area, thus forcing the operator to a 180° rotation.KeywordsErgonomicMusculoskeletal disordersMuscle fatigue3DSSPP