Majid Shahbazi, Javad Sarrafzadeh, Saeed Akhlaghi, Hossein Negahban,
Volume 12, Issue 4 (Iranian Journal of Ergonomics-In Press 2025)
Abstract
Background: 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.
