Acute and chronic remote flexibility effects following stretching, foam rolling and manual techniques on the posterior myofascial chain – a systematic review with meta-analysis

Introduction This systematic review with meta-analysis investigated the acute and chronic remote flexibility effects of stretching, foam rolling, and manual techniques (also with tool-use) applied along the posterior myofascial chain. Additionally, we examined potential effect modifiers. Methods We performed a systematic literature search in PubMed and Web of Science and included controlled trials assessing acute and chronic non-local flexibility effects of these interventions in the posterior myofascial chain of healthy adults. Risk of bias was assessed with the RoB2 and the ROBINS-I scales. We applied robust variance estimation to pool the effects between intervention and control (placebo, inactive, sham). Meta-regression was used to identify potential effect modifiers. Results We identified 16 randomized controlled trials and 2 controlled trials (all low to medium risk of bias). Local interventions induced a moderate acute increase in distant posterior myofascial chain flexibility (SMD: -0.74, 95% CI: -0.95 to -0.54, p<.001, 15 studies). Meta-regression revealed similar estimates for most levels of effect modifiers. We found only three long-term studies with ambiguous results not allowing for definitive conclusions. Discussion Local interventions applied in the posterior myofascial chain acutely increase remote flexibility. Nevertheless, the findings must be interpreted with caution (low number of studies) and generalizability might be limited. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/view/CRD42023482938 , identifier CRD42023482938.