Effects of Manual Therapy on the Diaphragm in the Musculoskeletal System: A Systematic Review

Objectives: To analyze the effects at the musculoskeletal level of manual treatment of the diaphragm muscle in adults. Data Sources: Systematic review using 4 databases: PubMed, Science Direct, Web of Science, and Scopus. Study Selection and Data Extraction: Two independent reviewers applied the selection criteria and assessed the quality of the studies using the Physiotherapy Evidence Database scale for experimental studies. A third reviewer intervened in cases where a consensus had not been reached. A total of 9 studies were included in the review. Data Synthesis: Manual therapy directed to the diaphragm has been shown to be effective in terms of the immediate increase in diaphragmatic mobil-ity and thoracoabdominal expansion. The immediate improvement in the posterior muscle chain flexibility test is another of the most frequently found findings in the evaluated studies. Limited studies show improvements at the lumbar and cervical level in the range of motion and in pain. Conclusion: Manual diaphragm therapy has shown an immediate significant effect on parameters related to costal, spinal, and posterior muscle chain mobility. Further studies are needed, not only to demonstrate the effectiveness of manual diaphragm therapy in the long-term and in symp-tomatic populations, but also to investigate the specific neurophysiological mechanisms involved in this type of therapy.