Effects of Resistance Training on Pain Control and Physical Function in Older Adults With Low Back Pain: A Systematic Review With Meta-analysis.

Background and purpose: Low back pain (LBP) has a high prevalence in older adults and is associated with elevated health care costs. This systematic review and meta-analysis examines the effects of progressive resistance training (PRT) interventions on physical function (PF) and pain control in community-dwelling older adults with chronic LBP.

Methods: A meta-analysis applying the quality effect method was performed by calculating the effect sizes (ESs) using the Cohen d with a 95% CI. A subgroup analysis was performed according to the participant and intervention characteristics. The statistical significance of differences between subgroups was calculated using a Z -test. Study bias was estimated using the version 2 of the Cochrane risk of bias tool for randomized trials (RoB 2.0) and quality of evidence (Qi) index. Small study effect/publication bias was estimated using the Doi plot and Luis Furuya-Kanamori (LFK) index. The systematic search was conducted in major databases for clinical trials published between January 1, 1990, and January 9, 2021. The inclusion criteria were articles that (1) were peer-reviewed; (2) had participants' mean age of more than 60 years; (3) studied PRT interventions; (4) had participants with LBP; (5) measured LBP or PF outcomes; (6) measured PF in terms of functionality; (7) were randomized controlled trials; (8) and non-randomized controlled trials. The exclusion criteria were (1) articles not written in English, (2) nonexperimental studies, and (3) repeated publications.

Results and discussion: Twenty-one studies were included (n = 1661). Clear improvements were found in PF (ES = 0.32 [95% CI, 0.05-0.58]; I2 = 75.1%; P < .001), but results on LBP decrease were inconclusive (ES = 0.24 [95% CI, -0.05 to 1.10]; I2 = 75.7%; P < .001). The overall evidence of this aggregated data meta-analysis of clinical trials is level C+. Main limitations are the use of aggregated data and the large heterogeneity between studies.

Conclusions: The Qi of this meta-analysis is level I (C+). We concluded that PRT interventions are useful for PF improvement in older adults with generalized LBP, LBP not arising from lumbar spinal stenosis, and having body mass index less than 27. In older adults with LBP not arising from lumbar spine stenosis, PRT interventions also decrease LBP. Interventions should have a frequency of at least 3 sessions per week. In addition, at a lower level of evidence IV (C+), we recommend that interventions with a duration of more than 12 weeks should be considered, whenever possible.