Table 2

Occupational exposure to knee-straining activities: proportion of exposed and nonexposed subjects among cases and controls

Exposed

Not exposed

No indication

Exposure

Gender

Controls/cases

n

%

n

%

n

%

Sitting

Female

Controls

261

86.2

28

9.2

14

4.6

Cases

367

83.8

60

13.7

11

2.5

Male

Controls

228

85.1

34

12.7

6

2.2

Cases

239

79.4

53

17.6

9

3.0

Standing

Female

Controls

240

79.2

49

16.2

14

4.6

Cases

363

82.9

64

14.6

11

2.5

Male

Controls

226

84.4

36

13.4

6

2.2

Cases

249

82.7

43

14.3

9

3.0

Walking

Female

Controls

249

82.2

40

13.2

14

4.6

Cases

381

87.0

46

10.5

11

2.5

Male

Controls

241

90.0

21

7.8

6

2.2

Cases

266

88.4

26

8.6

9

3.0

Kneeling, squatting

Female

Controls

113

37.3

176

58.1

14

4.6

Cases

215

49.1

212

48.4

11

2.5

Male

Controls

118

44.1

144

53.7

6

2.2

Cases

163

54.5

129

42.5

9

3.0

Climbing stairs

Female

Controls

186

61.4

104

34.3

13

4.3

Cases

317

72.4

111

25.3

10

2.3

Male

Controls

181

67.6

81

30.2

6

2.2

Cases

220

73.1

75

24.9

6

2.0

Jumping

Female

Controls

46

15.3

244

80.5

13

4.2

Cases

91

20.8

337

76.9

10

2.3

Male

Controls

79

29.5

183

68.3

6

2.2

Cases

120

39.8

173

57.5

8

2.7

Lifting/carrying of loads

Female

Controls

101

32.0

144

47.5

62

20.5

Cases

152

35.7

190

43.4

96

21.9

Male

Controls

162

60.4

87

32.5

19

7.1

Cases

196

65.1

83

27.6

22

7.3

Klussmann et al. Arthritis Research & Therapy 2010 12:R88   doi:10.1186/ar3015