Majid Shahbazi, Javad Sarrafzadeh, Saeed Akhlaghi, Hossein Negahban,
Volume 12, Issue 4 (Iranian Journal of Ergonomics 2025)
Abstract
Objectives: Balance control is a crucial issue in patients with low back pain. Despite existing studies, the mechanism of balance control in patients with low back pain, especially under different loading conditions at various heights, remains unclear. Therefore, this study aimed to investigate the effect of height on balance during loading.
Methods: In this cross-sectional study, 54 low back pain patients and 20 healthy male individuals participated. Balance control was assessed using a force plate system. The participants were randomly instructed to lower the load from above the head to waist level and from waist level to the ground. The load was approximately 10% of the participants' body weight. The P value was established 5% level of significance.
Results: The results showed that during lifting from above the head to waist level and from waist level to the ground, there were significant differences (P<0.05) in variables such as medial-lateral and anterior-posterior velocity, total mean velocity, and center of pressure displacement in the anterior-posterior direction between the two groups. Intra-group comparisons of variables in healthy individuals and low back pain patients indicated significant differences (P<0.05) in all variables except anterior-posterior velocity in healthy individuals. Both groups exhibited increased postural sway while lowering at a lower height.
Conclusion: The present study demonstrates that both healthy individuals and low back pain patients display less balance when loading at a lower height with a flexed lumbar spine, indicating that considering these findings could contribute to rehabilitation, determining occupational conditions, and preventing workplace-related accidents.
Fatemeh Hajialikhani, Fatemeh Shahbazi, Neda Mahdavi,
Volume 14, Issue 2 (Iranian Journal of Ergonomics-In Press 2026)
Abstract
Background and Objective: Handicraft artists in Isfahan Province are at heightened risk of developing upper‑extremity musculoskeletal disorders due to the nature of their work, which involves repetitive movements and awkward postures. This study was conducted to examine the influence of hand‑tool characteristics on upper‑extremity musculoskeletal discomfort among these artisans.
Methods: In this cross-sectional analytical study, 191 artisans (70 women and 121 men) working in the fields of enameling, turquoise inlaying, miniature painting, and metal engraving were selected through random sampling. Data were collected using demographic questionnaires, the Quick version of Disabilities of the Arm, Shoulder and Hand (Quick-DASH) questionnaire, and the Comfort QH (CQH) tool comfort questionnaire. Statistical analyses were conducted using Stata version 17, and a significance level of less than 0.05 was considered for all statistical tests.
Results: The mean and standard deviation of the Quick-DASH score were estimated at 28.89 and 4.91, respectively. The highest Quick-DASH score was related to the engravers, with a mean of 30.89 and a standard deviation of 2.91. Work experience was a factor influencing the Quick-DASH score (P = 0.003). The mean CQH questionnaire score for artists was 1.09 with a standard deviation of 0.26. Turquoise inlay workers and engravers had the most discomfort from the tools, with a mean (standard deviation) of 1.04(0.23). No significant correlation was observed between upper limb disability and tool comfort.
Conclusion: The handicraft artists of Isfahan, who routinely perform highly repetitive and fine manual tasks, are exposed to a considerable risk of developing musculoskeletal disorders. Although no statistically significant association was found between musculoskeletal disability and discomfort related to hand tools, both univariate and multivariate analyses highlighted the substantial impact of hand‑tool comfort on upper‑extremity musculoskeletal discomfort.
