(10) How is your posture? (bending forward, stoop, constant looking down)

1. Good

2. Bad

3. Can’t say

1. Good

2. Bad

3. Can’t say

(11) Do you have stiff neck, stiff back or stiff shoulder?

1. Severe

2. To some extent

3. A little

4. None

1. Severe

2. To some extent

3. A little

4. None

(12) Did you spend more time sitting or sleeping after having smartphone?

1. Yes

2. No

3. Can’t say

(13) How long do you spend in your room on holidays?

1. Most of the time

2. Long hours

3. A few hours

4. A little time

1. Most of the time

2. Long hours

3. A few hours

4. A little time

(14) Did you ever notice your physical fitness become worse after having smartphone?

1. Very

2. To some extent

3. A little

4. None

III. About sleep

(15) Time spent using smartphones before actual sleeping?

*Please fill in the “before having smartphone” for conventional mobile phone use

1. <30 min

2. 30 min ~ 1 hr

3. 1 ~ 2 hrs

4. 2 ~ 4 hrs

5. >5 hrs

1. <30 min

2. 30 min ~ 1 hr

3. 1 ~ 2 hrs

4. 2 ~ 4 hrs

5. >5 hrs

(16) When is your bedtime?

1. Before 22 o’clock

2. 22 ~ 24 o’clock

3. 24 ~ 2 o’clock

4. 2 ~ 4 o’clock

5. After 4 o’clock

1. Before 22 o’clock

2. 22 ~ 24 o’clock

3. 24 ~ 2 o’clock

4. 2 ~ 4 o’clock

5. After 4 o’clock

(17) How many hours do you sleep a day?

1. <5 hrs

2. 5 ~ 6hrs

3. 6 ~ 7hrs

4. 7 ~ 8hrs

5. >8 hrs

1. <5 hrs

2. 5 ~ 6 hrs

3. 6 ~ 7 hrs

4. 7 ~ 8 hrs

5. >8 hrs

(18) Do you have feeling of sufficient sleep every day?

1. Yes

2. No

3. Can’t say

1. Yes

2. No

3. Can’t say

(19) Do you have problems with sleep as specified on the right? (Multiple answers allowed)

1. I can’t sleep well

2. Superficial sleep

3. I wake up many times at night

4. Short sleep time

5. Still tired even after sleep

6. No problem

1. I can’t sleep well

2. Superficial sleep

3. I wake up many times at night

4. Short sleep time

5. Still tired even after sleep

6. No problem