Background: Exercise therapy is widely used as an intervention in low-back pain.
Objectives: To evaluate the effectiveness of exercise therapy in adult non-specific acute, subacute and chronic low-back pain versus no treatment and other conservative treatments.
Search strategy: The Cochrane Central Register of Controlled Trials (Issue 3, 2004), MEDLINE, EMBASE, PsychInfo, CINAHL databases to October 2004; citation searches and bibliographic reviews of previous systematic reviews.
Selection criteria: Randomized controlled trials evaluating exercise therapy for adult non-specific low-back pain and measuring pain, function, return-to-work/absenteeism, and/or global improvement outcomes.
Data collection and analysis: Two reviewers independently selected studies and extracted data on study characteristics, quality, and outcomes at short, intermediate, and long-term follow-up.
Main results: Sixty-one randomized controlled trials (6390 participants) met inclusion criteria: acute (11), subacute (6) and chronic (43) low-back pain (1 unclear). Evidence was found of effectiveness in chronic populations relative to comparisons at all follow-up periods; pooled mean improvement was 7.3 points (95% CI, 3.7 to 10.9) for pain (out of 100), 2.5 points (1.0 to 3.9) for function (out of 100) at earliest follow-up. In studies investigating patients (i.e. presenting to healthcare providers) mean improvement was 13.3 points (5.5 to 21.1) for pain, 6.9 (2.2 to 11.7) for function, representing significantly greater improvement over studies where participants included those recruited from a general population (e.g. with advertisements). There is some evidence of effectiveness of graded-activity exercise program in subacute low-back pain in occupational settings, though the evidence for other types of exercise therapy in other populations is inconsistent. There was evidence of equal effectiveness relative to comparisons in acute populations [pain: 0.03 points (95% CI, -1.3 to 1.4)].
Limitations: This review largely reflects limitations of the literature, including low quality studies with heterogeneous outcome measures, inconsistent and poor reporting, and possibility of publication bias.
Authors' conclusions: Exercise therapy appears to be slightly effective at decreasing pain and improving function in adults with chronic low-back pain, particularly in healthcare populations. In subacute low-back pain there is some evidence that a graded activity program improves absenteeism outcomes, though evidence for other types of exercise is unclear. In acute low-back pain, exercise therapy is as effective as either no treatment or other conservative treatments.