Assessment and virtual redesign of a manual handling workstation by computer-aided three-dimensional interactive application.
BACKGROUND
Manual handling of bags which imposes frequent forces and stresses on body parts is a common task that many workers have to perform every day. The present study aimed to assess the postural risk and imposed forces due to manual handling and loading of sugar bags.


METHODS
This study was conducted on male warehouse workers of a sugar manufacturing plant. Rapid upper limb assessment (RULA) was used to assess the risks of awkward postures and computer-aided three-dimensional interactive application to estimate the forces and moments.


RESULTS
RULA final scores were estimated to be 7 and 3 before and after the virtual redesign, respectively. Postures B and E obtained the highest compression forces and moments. The compression forces were higher than the action limit (AL) in all postures before the redesign and exceeded the maximum permissible limit (MPL) in posture E. After the redesign, these forces were reduced below the AL and MPL. Moreover, the shearing forces were lower than the AL and MPL in all postures.


CONCLUSIONS
The main risk factors were heavy weight and poor control of sugar bags. Virtual redesign can diminish bending and twisting postures, and, therefore, some resulting forces and moments.
a Shiraz University of Medical Sciences , Iran.|b Bushehr University of Medical Sciences , Iran.
Mansour
M
Ziaei
c Kermanshah University of Medical Sciences , Iran.
Hojjat
H
Ziaei
c Kermanshah University of Medical Sciences , Iran.
Seyed Younes
SY
Hosseini
c Kermanshah University of Medical Sciences , Iran.
Faramarz
F
Gharagozlou
d University of Social Welfare and Rehabilitation Sciences , Iran.
Ali Akbar
AA
Keikhamoghaddam
e Tehran University of Medical Sciences , Iran.
Marzieh Izadi
MI
Laybidi
c Kermanshah University of Medical Sciences , Iran.
Mehdi
M
Moradinazar
D000328:Adult; D003198:Computer Simulation; D006804:Ergonomics / Q000379:methods; D006801:Humans; D008297:Male; D000072499:Manufacturing and Industrial Facilities; D011187:Posture / Q000502:physiology*; D012307:Risk Factors; D012984:Software; D000073893:Sugars; D013647:Task Performance and Analysis; D034941:Upper Extremity / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology*
D000073893:Sugars
computer-aided three-dimensional interactive application; manual materials handling; sugar industry; workstation