Constructs and questions | Scoring | Mean ± SD | CVR | S-CVI | Factor loading | Cronbach’s alpha | Composite reliability | AVE | T-value |
---|---|---|---|---|---|---|---|---|---|
Predisposing factors (Perceived susceptibility) | 4 to 12 | 7.71 ± 2.35 | 0.95 | ≥0.70 |  | 0.60 | 0.79 | 0.56 |  |
 If I carry a heavy bag, I’ll get pain in my back, neck and shoulders. |  |  |  |  | 0.81 |  |  |  | 11.42 |
 If is lift my bag with one hand, my spines would be tilted and my shoulders dropped. |  |  |  |  | 0.75 |  |  |  | 12.82 |
 I won’t get pain in my back, neck and shoulders because I’m too young. |  |  |  |  | 0.66 |  |  |  | 8.18 |
Predisposing factors (Perceived severity) | 4 to 12 | 8.97 ± 2.43 | 0.95 | ≥0.70 |  | 0.72 | 0.82 | 0.54 |  |
 Pain in my back, neck and shoulders makes me not attend school. |  |  |  |  | 0.82 |  |  |  | 18.62 |
 Pain in my neck, back and shoulders makes me not concentrate in class. |  |  |  |  | 0.75 |  |  |  | 11.95 |
 Pain in my back, neck and shoulders is a serious disease. |  |  |  |  | 0.75 |  |  |  | 8.69 |
 Pain in my back, neck and shoulders makes me take drugs. |  |  |  |  | 0.61 |  |  |  | 5.71 |
Predisposing factors (Perceived benefits) | 5 to 15 | 11.35 ± 2.86 | 0.84 | ≥0.70 |  | 0.73 | 0.82 | 0.54 |  |
 If I put on both the shoulder straps of my backpack, it prevents me from back, shoulder and neck pains |  |  |  |  | 0.68 |  |  |  | 7.17 |
 I won’t get back, shoulder and neck pains if I have a lighter backpack. |  |  |  |  | 0.69 |  |  |  | 7.56 |
 Carrying a light backpack makes me not hunch out. |  |  |  |  | 0.79 |  |  |  | 15.25 |
 Tying hip straps of my backpack would bring me healthier neck, back and shoulders. |  |  |  |  | 0.77 |  |  |  | 14.17 |
Predisposing factors (Perceived barriers) | 3 to 9 | 6.54 ± 2.25 | 0.90 | ≥0.70 |  | 0.85 | 0.91 | 0.77 |  |
 I’m too lazy to put my books in my backpack according to my daily schedule. |  |  |  |  | 0.78 |  |  |  | 12.38 |
 Tying hip straps of my backpack would make me uncomfortable. |  |  |  |  | 0.93 |  |  |  | 50.63 |
 My teacher wants me to bring all my books and notebooks every day. |  |  |  |  | 0.92 |  |  |  | 54.39 |
Predisposing factors (Perceived self-efficacy) | 4 to 12 | 7.89 ± 2.86 | 0.85 | ≥0.70 |  | 0.88 | 0.92 | 0.74 |  |
 I can always tie hip straps of my backpack even if it makes me uncomfortable. |  |  |  |  | 0.86 |  |  |  | 23.63 |
 I can always put on both two shoulder strap of my backpack to carry it. |  |  |  |  | 0.88 |  |  |  | 34.42 |
 I can only have books of my schedule; I usually keep extra items out of my bag. |  |  |  |  | 0.86 |  |  |  | 25.23 |
 I can always put heavier books in the back of the backpack which is nearer to my back. |  |  |  |  | 0.83 |  |  |  | 19.79 |
Reinforcing factors | 3 to 9 | 5.02 ± 1.75 | 0.86 | ≥0.70 |  | 0.58 | 0.77 | 0.54 |  |
 My teachers or schools nurses encourage me to lift and carry my backpack properly. |  |  |  |  | 0.87 |  |  |  | 23.73 |
 My friends encourage me to lift and carry my backpack properly. |  |  |  |  | 0.69 |  |  |  | 7.40 |
 My parents and other siblings encourage me to lift and carry my backpack properly. |  |  |  |  | 0.62 |  |  |  | 5.69 |
Enabling factors | 5 to 15 | 8.54 ± 2.31 | 0.92 | ≥0.70 |  | 0.69 | 0.81 | 0.52 |  |
 My teachers or schools nurses taught me to lift and carry my backpack properly. |  |  |  |  | 0.71 |  |  |  | 2.72 |
 My friends taught me to lift and carry my backpack properly. |  |  |  |  | 0.70 |  |  |  | 2.75 |
 My parents and other siblings taught me to lift and carry my backpack properly. |  |  |  |  | 0.74 |  |  |  | 2.29 |
 TV programs (Media) taught me to lift and carry my backpack properly |  |  |  |  | 0.73 |  |  |  | 2.43 |
Behaviors | 4 to 12 | 6.71 ± 2.07 |  |  |  | 0.66 | 0.79 | 0.50 |  |
 I always put both two shoulder strap of my backpack. |  |  |  |  | 0.76 |  |  |  | 13.23 |
 I always tie hip straps of my backpack. |  |  |  |  | 0.47 |  |  |  | 4.22 |
 To lift my bag, I first put it on my seat first and then keep it on my shoulders |  |  |  |  | 0.79 |  |  |  | 17.57 |
 I always put heavy books in the back of my backpack. |  |  |  |  | 0.74 |  |  |  | 13.98 |