Penrose 1991.

Methods	RCT
Participants	Subjects: 30 patients, 8 women and 22 men. Mean age 34 years (range 19 ‐ 61 years). Patients were diagnosed as having muscular strain/sprain of the lower back by an orthopedic‐neurologic examination. No information available on mean duration of complaints.
Interventions	Treatment intervention: 1) Pneumatic lumbar support (n=15). Lumbar support use during 6 hours / day, 5 days / week, 6 weeks. Control intervention: 2) No intervention.
Outcomes	Pain index; lumbar supports better after 1 hour, 3 weeks and 6 weeks.
Notes	No data on compliance.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Unclear from text
Allocation concealment?	Low risk	A ‐ Adequate
Blinding? All outcomes ‐ patients?	High risk
Blinding? All outcomes ‐ outcome assessor?	High risk
Incomplete outcome data addressed? All outcomes ‐ drop‐outs?	Low risk
Incomplete outcome data addressed? All outcomes ‐ ITT analysis?	Low risk
Similarity of baseline characteristics?	Unclear risk	Unclear from text
Co‐interventions avoided or similar?	High risk
Compliance acceptable?	Unclear risk	No data on compliance.
Timing outcome assessments similar?	Low risk