Affiliations: Department of Occupational Health, School of Public Health and Research Centre for Health Sciences, Hamadan University of Medical Sciences, Hamadan, Iran | Ergonomics Department, School of Public Health and Research Centre for Health Sciences, Hamadan University of Medical Sciences, Hamadan, Iran | School of Rehabilitation, Musculoskeletal Rehabilitation Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran | Department of Biostatistics and Epidemiology and Research Center for Health Sciences, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran
Note: [] Corresponding author: Majid Motamedzade, Department of Ergonomics, School of Public Health and Research,
Center for Health Sciences, Hamadan University of Medical Sciences, Hamadan, Iran. Tel.: +98 811 8380025; Fax: +98 811 8380509; E-mail: [email protected]
Abstract: BACKGROUND: Work-related musculoskeletal disorders of back among
weavers are prevalent. Epidemiological studies have shown an association
between poor working postures and back disorders among carpet weavers.
Therefore, the present study aimed to evaluate the impact of the traditional
(A) and ergonomically designed (B) workstations on trunk posture and cumulative
compression load in carpet weavers. METHODS: In this study, subtasks were identified in terms of
stressful postures and carpet weaving process. Postural data were collected
during knotting and compacting subtasks using inclinometer during four hours
for each workstation. Postural data, weight and height of the weavers were
entered into the University of Michigan three-dimensional static biomechanical
model for estimation of the compression load and cumulative load were estimated
from the resultant load and exposure time. PARTICIPANTS: Thirteen healthy carpet weavers (four males and nine
females) participated in the study. RESULTS: Median trunk flexion angle was reduced with workstation B
during knotting subtask (18° versus 8.5°, p< 0.01 in males;
18.5° versus 7°, p< 0.001 in females). Average cumulative
compression load was reduced with workstation B (22.17MN-s versus 16.68MN-s, p
< 0.01 in males; 13.05 MN-s versus 10.14, p < 0.001 in females). CONCLUSIONS: Using workstation B led to significant decrease in
cumulative compressive loading during an entire shift (8 hours), which
indicates reduced level of stress on the back. It is suggested to conduct
biomechanical studies on the shoulder and wrist regions in carpet weavers in
order to achieve further development and improvement in the ergonomically
designed workstation.
