The Risk Assessment of Low Back Pain Based on Allowable Weight Limits for Manual Lifting in Iranian Women Workers

Manual load lifting is one of the most important risk factors for musculoskeletal disorders, including occupational low back pain. These disorders are common in women workers who perform manual load lifting and displacement tasks at the workplace.

To determine the level of musculoskeletal disorders and to evaluate the recommended limits of manual load lifting in women workers using WISHA checklist and ACGIH TLV, the recommended limits of Iran, and compare the results of two methods.

This cross-sectional study was conducted on 100 women workers who performed manual loading tasks in 2018. Nordic questionnaire was used to determine the prevalence of musculoskeletal disorders, and two methods, WISHA checklist and ACGIH TLV, were used to determine the recommended allowable limits for manual load lifting.

The results of the prevalence assessment of musculoskeletal disorders showed that most of the musculoskeletal disorders were in the low back (55%) in the past 12 months. The results of the assessment of the allowable lifting limits also showed that 8% of women in the WISHA checklist method and 31% in the ACGIH TLV method were at risk for low back injuries. The kappa coefficient test (0.031) also showed that there is a poor and insignificant agreement between the two methods of WISHA checklist and ACGIH TLV in determining the allowable limits for manual lifting.

The results of this study showed a poor agreement between the WISHA checklist and ACGIH TLV in determining the allowable limits for manual lifting, which suggest that the two methods are not mutually exclusive. Hence, owing to the increasing presence of women in various occupations and raising the hand load-lifting and, naturally increasing occupational low back pain among them, it is necessary that in a comprehensive study, the allowable limits of lifting loads according to anthropometric and physiological characteristics of Iranian women, prepare and compile according to a comprehensive instruction.