| Study characteristics |
| Methods |
Study design: RCT
Setting: South Korea, healthcare
Exercise groups: 2
Comparison groups: 0 |
| Participants |
Number of participants: 27 (E1 = 14, E2 = 13)
Chronic LBP duration: 12.77 months (moderate)
Neurological/radicular symptoms: Not specified
Mean age (years): 33
Sex (female): 63% |
| Interventions |
Exercise Group 1 (E1): Lumbar stabilisation with Flexi‐Bar: participants conducted the abdominal drawing‐in manoeuvre in standing, hook‐lying, quadruped, and prone positions by maintaining each motion for 10 seconds; type = core strengthening; duration = 6 weeks; dose = low; design = standardised; delivery = group; additional intervention = none
Exercise Group 2 (E2): Lumbar stabilisation only: abdominal drawing‐in manoeuvre in standing, hook‐lying, quadruped, and prone positions by maintaining each motion for 10 seconds; type = core strengthening; duration = 6 weeks; dose = low; design = standardised; delivery = group; additional intervention = none |
| Outcomes |
Core outcomes reported: Pain (Visual Analogue Scale); function (Oswestry Disability Index)
Follow‐up time periods available for syntheses: 6 weeks (short) |
| Notes |
Conflicts of interest: None to declare
Funding source: Not reported
Other: SDs imputed |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Only cited as "randomized" |
| Allocation concealment (selection bias) |
High risk |
No description of randomisation process to assess concealment of treatment allocation |
| Blinding of participants and personnel (performance bias)
All outcomes |
Low risk |
1. Patients could not be blinded to their intervention due to the nature of the treatments; 2. Both groups receiving exercise and would be difficult to access the experimental protocol outside of the study context. |
| Blinding of care provider (performance bias) |
Low risk |
1. Care providers could not be blinded to allocation due to the nature of the treatments; 2. Unlikely that lack of care provider blinding led to deviations from protocol, as their role in each treatment group was nearly identical, aside from Flexi‐bar inclusion. |
| Blinding of outcome assessment (detection bias)
All outcomes |
High risk |
1. For outcomes of interest (pain and disability) the outcome assessors were the participants, who could not be blinded due to the nature of the interventions; 2. Pain and functional questionnaires are subjective, and responses could be altered by awareness of intervention; 3. Control group receiving usual exercise whereas the experimental group received a intervention potential considered “trendy” that could alter response. |
| Incomplete outcome data (attrition bias)
All outcomes |
High risk |
1. No description of dropout rate 2. No evidence of the analysis correcting for bias, excluded those who did not have enough time to attend; 3. Increased low back pain or decreased function could cause missing outcome; 4. No information on missingness; 5. No information reported on those lost to follow‐up |
| Participants analysed in group allocated (attrition bias) |
Low risk |
1. All participants appeared to have been analysed according to their randomised allocation. |
| Selective reporting (reporting bias) |
Low risk |
1. No linked protocol found: within this paper there were no obvious omissions in outcomes or analyses. |
| Groups similar at baseline (selection bias) |
Low risk |
All relevant baseline characteristics were measured and were sufficiently similar between treatment groups. |
| Co‐interventions avoided or similar (performance bias) |
High risk |
No reporting of how study addressed co‐interventions |
| Compliance acceptable in all groups (performance bias) |
High risk |
No information on compliance/attendance reported |
| Timing of outcome assessment similar in all groups (detection bias) |
Low risk |
1. All outcomes were assessed at the same time; within each outcome, all participants were assessed using the same tools; 2. Visual Analogue Scale (for pain) and Oswestry Disability Index (for disability) are well‐validated tools in the context of low back pain. |
| Other bias |
Low risk |
Under reported, no other apparent sources of bias |
