Durmus 2013.

Study characteristics
Methods	RCT conducted in outpatient department (secondary care setting)
Participants	64 female patients who had been experiencing low back pain for at least 3 months were included. Exclusion criteria were: acute radicular signs or symptoms, radiographic evidence of inflammatory disease affecting the spine, tumour, spondylolysis, spondylolisthesis, or sacroiliitis, serious medical conditions for which exercise would be contraindicated, neuromuscular or dermatologic disease that involves the lumbar and abdominal area, were currently in an exercise programme, implanted cardiac pacemaker or defibrillator, contracture, previous trauma, history of spinal surgery, pregnancy, presence of severe structural deformity.
Interventions	Group 1 (n = 20) was given a group exercise programme for 60 min, 3 times per week for 6 weeks. Group 2 (n = 20) was given a 10‐minute ultrasound treatment (1 MHz frequency and 1.5 W/cm² intensity and a transducer head with an area of 5 cm, an effective radiating area of 4 cm, and a BNR of 1:5), 3 times per week for 6 weeks, and the same exercise programme as group 1. Group 3 (n = 20) was given phonophoresis therapy by applying 2 to 3 mm of capsaicin gel (10% capsicum oleoresin in 0.22% solution) then a 10‐minute ultrasound treatment (as per group 2), 3 times per week for 6 weeks, as well as the same exercise programme as group 1. Participants were evaluated pre‐treatment and after 6 weeks (post‐treatment).
Outcomes	60 participants completed the study. The post‐treatment (6‐week) between‐group comparison showed a significant difference in VAS pain, walking performance (6‐minute walk test), and extensor muscle strength in favour of groups 2 and 3 compared to group 1. There was no significant difference between groups 2 and 3. There was a significantly greater improvement in pain, physical function, and energy subscales of the SF‐36 in group 3 compared to groups 1 and 2.
Notes	No conflict of interest declared with regard to commercial funding.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method for determining randomisation sequence not reported in text.
Allocation concealment (selection bias)	Unclear risk	Not reported in text
Blinding of participants and personnel (performance bias) Participants	High risk	Participants not blinded to intervention.
Blinding of participants and personnel (performance bias) Care providers	High risk	Care providers not blinded.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Self‐reported primary outcome, participants not blinded to intervention
Incomplete outcome data (attrition bias) Dropout rate described	Low risk	Described and acceptable
Incomplete outcome data (attrition bias) Intention‐to‐treat	High risk	Dropouts excluded from analysis.
Selective reporting (reporting bias)	Unclear risk	No trial pre‐registration or published protocol was available.
Similar groups	Low risk	Groups were well matched at baseline.
Co‐interventions	Low risk	Medication controlled during intervention period.
Compliance	Unclear risk	Not reported in text
Timing of outcome measures	Low risk	Similar timing of outcome assessment (post‐treatment) for both groups