Table 2 Validity of the questionnaire and indices of measuring model for backpack carrying behaviors

Predisposing factors (Perceived susceptibility)

4 to 12

 If I carry a heavy bag, I’ll get pain in my back, neck and shoulders.

 If is lift my bag with one hand, my spines would be tilted and my shoulders dropped.

 I won’t get pain in my back, neck and shoulders because I’m too young.

Predisposing factors (Perceived severity)

4 to 12

 Pain in my back, neck and shoulders makes me not attend school.

 Pain in my neck, back and shoulders makes me not concentrate in class.

 Pain in my back, neck and shoulders is a serious disease.

 Pain in my back, neck and shoulders makes me take drugs.

Predisposing factors (Perceived benefits)

5 to 15

 If I put on both the shoulder straps of my backpack, it prevents me from back, shoulder and neck pains

 I won’t get back, shoulder and neck pains if I have a lighter backpack.

 Carrying a light backpack makes me not hunch out.

 Tying hip straps of my backpack would bring me healthier neck, back and shoulders.

Predisposing factors (Perceived barriers)

3 to 9

 I’m too lazy to put my books in my backpack according to my daily schedule.

 Tying hip straps of my backpack would make me uncomfortable.

 My teacher wants me to bring all my books and notebooks every day.

Predisposing factors (Perceived self-efficacy)

4 to 12

 I can always tie hip straps of my backpack even if it makes me uncomfortable.

 I can always put on both two shoulder strap of my backpack to carry it.

 I can only have books of my schedule; I usually keep extra items out of my bag.

 I can always put heavier books in the back of the backpack which is nearer to my back.

Reinforcing factors

3 to 9

 My teachers or schools nurses encourage me to lift and carry my backpack properly.

 My friends encourage me to lift and carry my backpack properly.

 My parents and other siblings encourage me to lift and carry my backpack properly.

Enabling factors

5 to 15

 My teachers or schools nurses taught me to lift and carry my backpack properly.

 My friends taught me to lift and carry my backpack properly.

 My parents and other siblings taught me to lift and carry my backpack properly.

 TV programs (Media) taught me to lift and carry my backpack properly

Behaviors

4 to 12

 I always put both two shoulder strap of my backpack.

 I always tie hip straps of my backpack.

 To lift my bag, I first put it on my seat first and then keep it on my shoulders

 I always put heavy books in the back of my backpack.