Background: Many of wrong behaviors like loading the heavy backpack causes to deformity of postural that increase the weight of them in recently twenty years. Thus, some researches focuses on the effects of abuse of backpack in the students. The aim of this study was to investigate the effect weight and duration of carrying backpacks on forward head, kyphoses and lordoses in girls 14 to 18 years.
Materials and Methods: According to Morgan’s sample size table (1994), 262 girls were selected on purpose (Means: age 15.5+_ 1.1years, height 160+_6 cm, weight 56.4 +_ 12.5 kg, BMI 21.9 +_ 4.4, weight backpack 3.98+_1.3 kg, duration of carrying 17.5+_ 8.5 min). Then, 45 girls were selected voluntarily and divided in three groups randomly on the basis of basic measurements. The forward head was measured by Goniometer, kyphoses by Kyphometer, lordoses by Flexible Ruler. Subjects carried backpack in three groups. First, weight of backpack 3.5 kg in 16 minutes, second, 4.8 kg in 21 minutes and third, 6.1 kg in 27 minutes, walking on the treadmill with 1.6 meters per second, Then all of variables were re-measured. The data were analyzed (with SPSS, version 20) using MANOVA, Tukey Post-Hoc (P≤0.05).
Results: showed that carrying backpacks more than 3.5 kg in average subjects weight there was significant increase in kyphoses angle (P≤0.05). Changes in forward head and lumbar lordoses angles showed no significant difference among the three groups.
Conclusion: Carrying heavy backpacks increased kyphoses in girls. So they should avoid carrying backpacks 6% heavier than their weight for more than 16 minutes.