Ljunggren 1984.

Methods	RCT (method of randomization not described)
Participants	52 hospitalized participants with lumbago‐sciatica and prolapsed lumbar intervertebral discs, admitted to neurological department, and considered for operation. Inclusion criteria: radicular signs L5 or S1 (or both) nerve root; symptoms aggravated or unchanged in last 2‐4 wk.
Interventions	T1) Auto‐traction and modified Gertrud Lind: traction force between 33% and 100% of participant's body weight; each pull for some seconds and sometimes up to 2 min. Every treatment lasted about 1 hour. T2) Manual traction and modified manual therapy. Traction force scarcely reached 300 N. Static traction given twice, each pull lasting for 5 min.
Outcomes	Immediately AT: overall assessment: no effect (number) T1) 21, T2) 15. Moderate effect (number): T1) 2, T2) 4. Good effect (number) T1) 3, T2) 4. At 2 wk: overall assessment: no effect (number) T1) 21, T2) 16. Moderate effect (number): T1) 1, T2) 4. Good effect (number) T1) 4, T2) 3. At 3 months: identical to results at 2 wk. Pain intensity (VAS) median (SD): BT: T1) 1.3 (0.3‐3.5), T2) 3.5 (0.9‐6.0). AT: T1) 0.8 (0‐1.8), T2) 1.6 (0.2‐3.0).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No mention of randomization procedure.
Allocation concealment (selection bias)	Unclear risk	No information provided on allocation concealment.
Blinding (performance bias and detection bias) All outcomes ‐ participants	Low risk	Participants were not informed about their participation in a randomized investigation with 2 treatment modalities.
Blinding (performance bias and detection bias) All outcomes ‐ providers	High risk	There is no mention of blinding of the care providers, but it is unlikely that they were.
Blinding (performance bias and detection bias) All outcomes ‐ outcome assessors	Low risk	The outcome assessor was blinded to the treatment allocation.
Incomplete outcome data (attrition bias) All outcomes ‐ loss to follow‐up	Low risk	3 participants (5.8%) were lost to follow‐up.
Incomplete outcome data (attrition bias) All outcomes ‐ intention to treat analysis	High risk	No intention‐to‐treat analysis was used.
Selective reporting (reporting bias)	Low risk	Published results included all prespecified outcomes.
Group similarity at baseline (selection bias)	High risk	Groups were not similar at baseline with regards to level of herniation, duration since first symptoms of sciatica and pain intensity in the lower back.
Influence of co‐interventions (performance bias)	Low risk	Participants were deprived of long‐term working analgesics later than hours prior to the traction session.
Compliance with interventions (performance bias)	Low risk	All participants were hospitalized, therefore, the compliance with the given treatment was high.
Timing of outcome assessments (detection bias)	Low risk	All important outcome assessments for all intervention groups were measured at the same time.