Saeed Ilbeigi, Zahra Karimi, Abbass Farjad Pezeshk,
Volume 13, Issue 2 (9-2025)
Abstract
Background and Purpose: Backpacks with pelvic belts are commonly used for carrying loads during long treks and mountaineering, as they help distribute the load between the upper and lower body and reduce muscular effort. However, they may also restrict movement. This study aimed to compare three common pelvic belt mechanisms in backpacks regarding their effects on postural control and center of pressure (COP) parameters during standing and walking.
Methods: This semi-experimental study was conducted on 20 male physical education students aged 19 to 25. Participants used three types of backpacks (1–with a movable pelvic belt, 2–with a crossed-frame back support, and 3–a regular backpack) while carrying a standard 13 kg load on a flat surface. A walking test without a backpack was also conducted as a control. COP indicators—including area, displacement, velocity, and sway—were measured. Data normality was assessed using the Shapiro-Wilk test, and statistical comparisons were made using repeated measures ANOVA and Bonferroni post hoc tests.
Findings: No significant differences were observed among the backpacks in terms of COP area during standing and walking. However, during eyes-closed standing, significant differences were found in COP displacement and velocity in the anterior-posterior direction (p=0.009), particularly between the regular backpack and the one with a movable pelvic belt. For COP sway (p=0.030), significant differences were found among the three backpacks in the medial-lateral direction, though pairwise comparisons showed no statistical significance.
Conclusion: The backpack with a movable pelvic belt showed superior performance in minimizing COP sway, displacement, and velocity. Differences in pelvic belt designs become more evident under higher complexity postural tasks.
