Urinary incontinence (UI), particularly stress urinary incontinence (SUI), significantly impacts quality of life, with pelvic floor muscle training (PFMT) established as a first-line intervention. The Knack maneuver—voluntary pre-contraction of pelvic floor muscles (PFM) during activities that increase intra-abdominal pressure—has been proposed as a complementary or alternative approach, yet its efficacy remains understudied. This meta-analysis synthesizes evidence on the effectiveness of the Knack maneuver in improving UI symptoms and PFM function.

We systematically searched PubMed, Scopus, and Web of Science for randomized controlled trials (RCTs) and prospective studies evaluating the Knack maneuver’s impact on UI outcomes (e.g., pad tests, ICIQ scores) and PFM parameters (e.g., strength). Study quality was assessed using the Newcastle-Ottawa Scale.

Five studies involving 284 participants were included. Knack training, particularly when combined with PFMT, significantly reduced urine leakage (mean difference: −14.8g pad test; 95% CI: −20.64, −8.96; p <0.00001) and improved symptom severity scores (ICIQ-SF: −2.35 points; 95% CI: −3.99, −0.71). PFM strength increased 11.90mmH2O (95% CI: 9.43–14.38; p <0.00001). In addition, 3 days bladder diary decreased 3.36 (95% CI: -5.99, -0.73; p <0.00001). All studies scored well on the NOS scale

The Knack maneuver demonstrates clinically meaningful improvements in UI symptoms and PFM function, especially when integrated with PFMT and structured education. While existing evidence supports its utility in mild-to-moderate SUI, further high-quality RCTs with long-term follow-ups are needed to standardize protocols and validate efficacy. Clinicians may consider incorporating Knack training into UI rehabilitation programs to enhance patient outcomes.