Table 1.

Characteristics of respondents.

Categories	N=164	%
Age
6 years old	11	6.7
7 years old	75	45.7
8 years old	74	45.1
9 years old	4	2.5
Gender
Male	81	49.4
Female	83	50.6
Grade
8th	68	41.5
9th	96	58.5
Learning method (curriculum)
Government standard	82	50
Modified	82	50
School Location
Urban	90	54.9
Suburban	74	45.1
Bag weight
Standardized	101	61.6
Not standardized	63	38.4
Back pain
No	111	67.7
Yes	53	32.3