Table 1 Validity of the questionnaire and indices of measuring model for sitting behaviors

Predisposing factors (Perceived susceptibility)

4 to 12

0.76

 If the sitting posture is not good I’ll have pain in my back, neck and shoulders

 Long-time sitting (more than 20 min) may cause pain in my back, neck and shoulders

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

Predisposing factors (Perceived severity)

4 to 12

0.82

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

 I am not being able to focus in class because of pain in back, neck and shoulders

 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)

4 to 12

0. 77

 If my sitting posture is accurate, I’ll get much less pain in my neck, shoulder and back.

 If I sit in a proper posture, I’ll have much more concentration while learning something

 If I sit in a proper posture my family won’t have to pay costs of back, shoulder and neck treatments

Predisposing factors (Perceived barriers)

9 to 27

0.91

 If I sit well in class, my classmates would make fun of me.

 If I sit in a proper posture,, I will get tired soon

 If I sit in a proper posture,, I will get distracted

 If I sit well in class, I can’t catch up with my friends in doing assignments.

 Improper furniture wouldn’t let me sit properly.

 The school has stairs so I can’t use a wheeled backpack.

 Stretching exercises make mess out of the class.

 The teacher doesn’t let us doing stretching.

 I will not get bored at home while doing stretching

Predisposing factors (Perceived Self-efficacy)

3 to 9

0.92

 I always sit on chairs (furniture) in a good posture.

 I sit well even if I’m tired.

 I can sit well for a long time (more than 20 min).

Reinforcing factors

6 to 18

0.81

 My teachers or school nurses encourage me to sit properly in the class

 My friends encourage me to sit properly in the class

 My parents and siblings encourage me to sit properly.

Enabling factors

5 to 15

0.80

 School furniture is good for proper sitting

 My teachers and school nurses taught me how to sit well.

 My friends taught me how to sit well.

 My parents and siblings taught me how to sit well.

Behaviors

4 to 12

0.81

 I put my forearms on the chair, when I’m sitting.

 When I’m sitting on the chair, I put my legs on the floor.

 While sitting, I lean my backrest on the chair and never bend over my book or notebook

 I do stretching when I get tired of sitting for a long time (after 20 min).