Before using smartphones

After starting to use smartphones

P value

Eyestrain

no

78

(30.0)

14

(5.4)

<0.001

a little

109

(41.9)

80

(30.8)

to some extent

56

(21.5)

108

(41.5)

severe

5

(1.9)

45

(17.3)

missing

12

(4.6)

13

(5.0)

Posture

cannot say

87

(33.5)

63

(24.2)

0.002

good

26

(10.0)

14

(5.4)

bad

137

(52.7)

177

(68.1)

missing

10

(3.8)

6

(2.3)

Stiffness of the neck, back and shoulders

no

57

(21.9)

29

(11.2)

<0.001

a little

80

(30.8)

56

(21.5)

to some extent

78

(30.0)

78

(42.7)

severe

35

(13.5)

59

(22.7)

missing

10

(3.8)

5

(1.9)

Level of activity on a holiday

no

41

(15.8)

32

(12.3)

<0.001

a little

68

(26.2)

63

(24.2)

to some extent

91

(35.0)

101

(38.8)

quite

44

(16.9)

54

(20.8)

missing

16

(6.1)

10

(3.8)

Constipation

no

131

(50.4)

125

(48.1)

ns

a little

60

(23.1)

66

(25.4)

moderate

40

(15.4)

46

(17.7)

severe

14

(5.4)

15

(5.8)

missing

15

(5.8)

8

(3.1)