Aluko 2013.

Study characteristics
Methods	Study design: RCT Recruitment period: July 2008–June 2010 Recruitment mode: participants were recruited from within a primary care musculoskeletal physiotherapy service provider within the London borough of Hillingdon. This unit provided a central base of treatment for people across the borough who were referred by their GP. Statistical analysis: outcome data analysed using multiple regression analysis where the baseline value was included as a covariate for each analysis. All data were skewed and log‐transformed, results are presented as the ratio geometric means with 95% CI. An ITT analysis was used with missing data replaced with the LOCF for incomplete data sets. Sample size calculation: in the absence of a known published clinically significant difference for the major outcome measure of mean trunk sagittal acceleration resulting from CSEs, it was not possible to use a standardised calculation to determine the appropriate sample size. The sample size was therefore derived from a similar study previously published.
Participants	Sample size: total: 33; EG1: 16; EG2: 17 Setting: primary care musculoskeletal physiotherapy service provider Country: UK Baseline characteristics Age in years, mean (SD): EG1: 36.2 (9.8); EG2: 35.8 (9.1) Sex, number (%) women: EG1: 13 women (81%); EG2: 15 women (88%) Duration LBP: ≤ 6 weeks; 22 (67%) of participants had a previous episode of acute NSLBP Inclusion criteria Onset of acute NSLBP with maximum duration of 6 weeks Exclusion criteria Degenerative conditions affecting the spine, diabetes, pregnancy, underlying neurologic conditions, active treatment of an ongoing spinal condition Active legal/compensation procedures History of depression History of multiple recurrent episodes of LBP Involvement in other research studies Not having English as primary language
Interventions	EG1: core stability class + stabilisation exercises Description: a core stability class consisting of both specific and global trunk exercises. Further instruction on 8 specific stabilisation muscles involving the transversus abdominis (TrA) and the lumbar multifidus (LM), abdominal hollowing while lying prone, alternate straight‐leg raise in supine, abdominal hollowing in sitting, Crook lying–alternate heel slide, 4‐point kneeling pelvic shift (side to side), trunk curl in crook lying, pelvic tilt in sitting, and alternate knee raise in sitting. 10 repetitions, 3 times/day. Materials/equipment: no Non‐exercise component: not reported Frequency and duration: 10 repetitions, 3 times/day for 6 weeks Delivery: supervised generic group lesson and unsupervised home programme Provider: PT EG2: core stability class Description: core stability class consisting of both specific and global trunk exercises Materials/equipment: no Non‐exercise component: not reported Frequency and duration: 3 times/day for 6 weeks Delivery: supervised generic group lesson and unsupervised home programme Provider: PT
Outcomes	Note: outcomes not designated as major or minor outcomes Pain: VAS (0–100) Baseline, mean (SD): EG1: 36.4 (23.2); EG2: 31.4 (22.0) 6 weeks, mean (SD): EG1: 31.8 (23.6); EG2: 26.7 (26.0) 3 months, mean (SD): EG1: 25.9 (23.2) EG2: 27.1 (26.7) Functional status: RMDQ Baseline, mean (SD): EG1: 8.6 (5.0); EG2: 10.5 (5.0) 6 weeks, mean (SD): EG1: 7.4 (5.4); EG2: 9.4 (5.8) 3 months, mean (SD): EG1: 6.8 (5.1); EG2: 8.4 (6.0) Other: trunk sagittal acceleration Adverse events: not reported
Notes	Authors' results and conclusions: the difference in pain and disability between the groups was statistically and clinically nonsignificant Funding: no funding sources reported Declaration of interest: no conflicts of interest reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The participants were randomly allocated"; "The randomisation was done by a colleague independent and blind to the study using concealed envelopes within which the group description was randomly placed within them."
Allocation concealment (selection bias)	Low risk	Quote: "The randomisation was done by a colleague independent and blind to the study using concealed envelopes."
Blinding All outcomes ‐ Participants	High risk	No mention of attempts to blind participants or their perceptions of the potential effectiveness of the different interventions.
Blinding All outcomes ‐ Healthcare providers	High risk	No mention of any attempts to blind care providers.
Blinding All outcomes ‐ outcome assessors	High risk	The outcome measures were self‐reported and participants were unblinded.
Influence of co‐interventions	Unclear risk	Personal communication: participants were requested not to seek additional treatment and the treating physiotherapists did not offer additional treatment. However, the study did not record whether participants sought other therapies.
Group similarity at baseline	Unclear risk	Study measured age, sex, height, weight. There were no differences between groups. No other baseline measures were reported.
Compliance	High risk	Personal communication: compliance was acceptable compared to clinical practice: 7/16 participants did no exercises; 4 participants did exercises some days (6, 7, 17, or 23 days); 5 participants did exercises all or most days.
Timing of outcome assessments	Low risk	Measurements at 3 weeks, 6 weeks, and 3 months of follow‐up.
Incomplete outcome data (attrition bias) Dropouts – all outcomes	High risk	Personal communication: flowchart with the number of dropouts: 11 in the exercise group, 11 in the control group.
Intention‐to‐treat‐analysis	Low risk	Quote: "An intention‐to‐treat analysis was used with missing data replaced with the Last Observation Carried Forward for incomplete data sets." The number of dropouts does not differ between groups.
Selective reporting (reporting bias)	Low risk	Pain intensity and function reported; no published protocol available.
Other bias	Unclear risk	No funding sources were reported. No official disclosure regarding potential conflicts of interest.