Table 4 Factor loadings identified using principal component analysis and the orthogonal VARIMAX rotation *

Work Station

Office equipment

Computer position

Desk at work has suitable height

0.80

-0.06

I can adjust my chair height

0.62

0.16

When I use the mouse my arm is supported

0.50

0.16

I have enough space to work at my desk

0.66

0.16

Keyboard is placed directly in front of me

0.14

0.87

Screen is placed directly in front of me

0.05

0.77

Eigenvalue

1.84

1.28

% of Variance

26.1

18.3

Body Posture

Awkward body posture

Head and body posture

I sit for long hours in one position

0.59

0.12

I sit with lifted shoulders.

0.72

0.10

Sitting in awkward posture

0.71

0.27

Performing repetitive tasks

0.77

0.02

Job physically exhausting

0.50

0.06

Head is twisted towards the left or right

0.30

0.74

Trunk is twisted towards the left or right

0.08

0.82

I sit in asymmetrical position

0.26

0.61

Eigenvalue

3.30

1.45

% of Variance

30.0

13.9

Job Control

Decision authority

Skill discretion

I decide how to perform my job task

0.74

0.04

I participate with others in decision

0.71

0.32

I decide my own task changes

0.68

0.39

I determine the time & speed job tasks

0.55

0.12

I solve work problems by my self

0.74

0.04

My work develop my abilities

0.28

0.62

At work I learn new things

0.05

0.68

Creative in my work

0.16

0.66

I undertake different tasks in my work

0.05

0.67

Eigenvalue

3.32

1.33

% of Variance

36.9

14.4

Job Demands

Work pressure

Task complexity

Work under extensive pressure

0.76

0.10

Difficulty to finish my job tasks

0.83

0.24

I take extra hours to finish

0.70

0.11

I speed to finish my tasks

0.59

0.26

No enough time to finish my job

0.73

0.02

I find my work tasks difficult

0.06

0.92

I have too many job tasks

0.23

0.89

Eigenvalue

3.225

1.36

% of Variance

46.5

19.5

Social Support

Social support

Work flow

My work sphere is good

0.69

0.14

I find support from colleges

0.65

0.56

I find support from supervisors

0.84

0.16

My colleagues are friendly

0.85

0.18

My supervisors are friendly

0.63

0.47

Work tasks depend on other colleges

0.51

0.62

The work flow goes smoothly

0.08

0.76

I can ask & enquire in my work

0.15

0.74

Eigenvalue

3.96

1.04

% of Variance

49.9

13.0

Break Time

Autonomy

Break quality

I can plan my work breaks

0.82

0.11

I can divide my work time

0.76

0.02

I can decide when to take a break

0.76

0.12

I alternate in my body posture

0.07

0.76

I alternate in my job task

0.20

0.82

I perform job task without computer

0.39

0.53

After two hours I take a break for 10 min

0.03

0.57

Eigenvalue

2.06

2.06

% of Variance

35.5

25.9