Table 1 Baseline characteristics of all participants (n = 246)

Age

41.1

10.7

39

Back pain intensity (1-10)

6.8

2.0

7

Pain during activity (1-9)

5.7

2.1

6

Pain while resting (1-9)

4.1

2.1

4

Roland Morris Questionnaire

8.8

4.3

9

Categorical variables

n

%

Civil status

   Married/cohabitant

192

78

   Single/widow/divorced

53

21.5

Education

   Public school 1-12 years

181

73.6

   University/Postgraduate college

41

16.7

HSCL-25

   Psychological distress (>1.75)

82

33.3

   No psychological distress (<1.75)

151

61.4

Perceived reduced ability to walk due to complaints

   Inability to walk more than 1 km

88

35.8

   Able to walk more than 1 km

131

53.3

Sleep problems due to pain:

   Some, often or all the time

193

78.5

   Never or seldom

48

19.5

Expectations regarding return to work:

   Negative expectations

140

56.9

   Positive expectations

93

37.8

Physiotherapy prior to participation in the trial:

   Had received PT prior to the trial

141

57.3

   Had not received PT prior to the trial

102

41.5

Perceived physical workload:

   Constant back strain more than half of the time

183

74.4

   Constant back strain less than half of the time

53

21.5

Previous sick leave episodes due to LBP:

   One or none previous episodes

107

43.5

   Two or more previous episodes

137

55.7