Arab 2016.

Study characteristics
Methods	Study design: RCT (NCT02178202) Setting: Iran, healthcare Exercise groups: 2 Comparison groups: 0
Participants	Number of participants: 14 (E1 = 7, E2 = 7) Chronic LBP duration: Not specified (not specified) Neurological/radicular symptoms: No participants Mean age (years): 37 Sex (female): 43%
Interventions	Exercise Group 1 (E1): Harmonic mobilisation technique: lower limb lifted by sling, patients asked to move leg side to side; type = flexibility/mobilising; duration = 2 weeks; dose = low; design = partially individualised; delivery = individual; additional intervention = none Exercise Group 2 (E2): End range loading, back extensions; type = core strengthening; duration = 2 weeks; dose = low; design = standardised; delivery = individual; additional intervention = none
Outcomes	Core outcomes reported: Pain (Numerical Rating Scale); function (Roland‐Morris Disability Questionnaire) Follow‐up time periods available for syntheses: 2 weeks (short)
Notes	Conflicts of interest: None to declare Funding source: No funding received Other: Information modified for author contact
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Used "the blocked randomization method (based on sample size in each group)"
Allocation concealment (selection bias)	High risk	No information on treatment allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	Low risk	1. Patients could not be blinded to allocation due to the nature of the treatments; 2. Unlikely that lack of patient blinding caused deviation from intended interventions because patients had no control over the delivery of intervention.
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 deviation from intended intervention because interventions were quite distinct and clearly prescribed.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	1. Outcome assessors for pain were the patients themselves, who could not be blinded due to the nature of the treatments; 2. Pain and function questionnaires are subjective and can be altered by knowledge of intervention; 3. No clear better intervention, both groups receiving active treatment, no reason to alter patient response.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	1. No description of dropout rate; 2. Analysis did not account for missing data; no sensitivity analysis; 3. Increased pain and function could cause missingness; 4. No indication of missing values; 5. No indication of missing values
Participants analysed in group allocated (attrition bias)	Low risk	1. Appeared that all patients were analysed according to the allocation to which they were randomised
Selective reporting (reporting bias)	Low risk	1. Study analysed and reported as described in methods section; protocol was registered (NCT02178202) but contained no pre‐planned outcomes.
Groups similar at baseline (selection bias)	Low risk	Groups were similar on all relevant characteristics at baseline, except did not report duration of symptoms.
Co‐interventions avoided or similar (performance bias)	Low risk	"To control the effects of other interventions, the patients were asked to abstain from exercise, medication use, and/or any type of modalities through the period of study".
Compliance acceptable in all groups (performance bias)	High risk	No information on compliance
Timing of outcome assessment similar in all groups (detection bias)	Low risk	1. Outcome assessments were identical for all patients, regardless of treatment group; 2. Numeric Rating Scale (for pain) and Roland‐Morris Disability Questionnaire (for function) are well‐validated tools in the low back pain context.
Other bias	Low risk	Appeared free from other sources of bias