| Study characteristics |
| Methods |
Study design: RCT
Setting: Denmark, healthcare
Exercise groups: 3
Comparison groups: 0 |
| Participants |
Number of participants: 105 (E1 = 33, E2 = 36, E3 = 36)
Chronic LBP duration: 780 weeks (long)
Neurological/radicular symptoms: No participants
Mean age (years): 45
Sex (female): 39% |
| Interventions |
Exercise Group 1 (E1): Intensive strengthening: trunk, back strengthening routine; type = core strengthening; duration = 12 weeks; dose = high; design = standardised; delivery = individual; additional intervention = not specified
Exercise Group 2 (E2): Back strengthening routine, similar to intensive less dose; type = core strengthening; duration = 12 weeks; dose = low; design = standardised; delivery = individual; additional intervention = not specified
Exercise Group 3 (E3): Isometric exercises for lumbar spine; type = strengthening; duration = 4 weeks; dose = low; design = standardised; delivery = not specified; additional intervention = electrotherapy |
| Outcomes |
Core outcomes reported: Pain (Visual Analogue Scale); function (Activities of Daily Living Scale)
Follow‐up time periods available for syntheses: 12 weeks (short); 39 weeks (moderate) |
| Notes |
Conflicts of interest: Not reported
Funding source: Danish Research Council and the Danish Health Foundation, Sygekassemcs Helsefond
Other: None |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Support for judgement is not available |
| Allocation concealment (selection bias) |
Low risk |
Support for judgement is not available |
| Blinding of participants and personnel (performance bias)
All outcomes |
High risk |
Support for judgement is not available |
| Blinding of care provider (performance bias) |
High risk |
Support for judgement is not available |
| Blinding of outcome assessment (detection bias)
All outcomes |
Low risk |
Support for judgement is not available |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
Support for judgement is not available |
| Participants analysed in group allocated (attrition bias) |
Low risk |
Support for judgement is not available |
| Selective reporting (reporting bias) |
Low risk |
Support for judgement is not available |
| Groups similar at baseline (selection bias) |
Low risk |
Support for judgement is not available |
| Co‐interventions avoided or similar (performance bias) |
Low risk |
Support for judgement is not available |
| Compliance acceptable in all groups (performance bias) |
High risk |
Support for judgement is not available |
| Timing of outcome assessment similar in all groups (detection bias) |
Low risk |
Support for judgement is not available |
