Outcomes	Illustrative comparative risks (95% CI)		Relative effect (95% CI)	No. of participants (studies)	Certainty of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	Exercise	Therapeutic ultrasound plus exercise
Lumbar flexion range of motion (ROM) (Schober test (cm); higher numbers mean increased ROM) Follow‐up: short term (post‐treatment)	The mean flexion ROM in the control groups ranged from 0.25 cm to 0.38 cm.	The mean flexion ROM in the intervention groups was 0.02 cm more (0.52 less to 0.56 more).	MD 0.02 (−0.52 to 0.56)	79 (2 RCTs)	⊕⊝⊝⊝ very low1,2	Estimate is not clinically important and is very uncertain.
Trunk flexor strength (hand‐held dynamometer (N·m); higher scores mean increased strength) Follow‐up: short term (post‐treatment)	The mean flexor strength in the control group was 23.2 N·m.	The mean flexor strength in the intervention group was 0.65 N·m more (0.23 less to 1.53 more).	MD 0.65 (−0.23 to 1.53)	40 (1 RCT)	⊕⊝⊝⊝ very low1,2	Estimate is not clinically important and is very uncertain.
Trunk flexor endurance (sit‐up test (seconds); higher numbers mean increased endurance) Follow‐up: short term (post‐treatment)	The mean trunk flexor endurance in the control group was 89.3 seconds.	The mean trunk extensor endurance in the intervention groups was 4.00 seconds more (1.09 more to 6.91 more).	MD 4.00 (1.09 to 6.91)	40 (1 RCT)	⊕⊝⊝⊝ very low1,2	Estimate is not clinically important and is very uncertain.
Trunk extensor endurance (Biering‐Sorensen test (seconds); higher numbers mean increased endurance) Follow‐up: short term (post‐treatment)	The mean trunk extensor endurance in the control group was 126.7 seconds.	The mean trunk extensor endurance in the intervention groups was 37.35 seconds more (33.29 more to 41.41 more).	MD 37.35 (33.29 to 41.41)	40 (1 RCT)	⊕⊝⊝⊝ very low1,2	Estimate is not clinically important and is very uncertain.
Abbreviations: CI: confidence interval; MD: mean difference; RCT: randomised controlled trial; ROM: range of motion
GRADE Working Group grades of evidence High certainty: Further research is very unlikely to change our confidence in the estimate of effect. Moderate certainty: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low certainty: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low certainty: We are very uncertain about the estimate.