Here is a paper released early in 2017 in The Journal of Bodywork and Movement Therapies that provides a narrative review of proposed effects of indirect and direct techniques.
Article: Parravicini, G., Bergna, A,. (2017). Biological effects of direct and indirect manipulation of the fascial system. Narrative review. Journal of Bodywork and Movement Therapies.
Introduction: Osteopathic Manipulative Treatment (OMT) is effective in improving function, movement and restoring pain conditions. Despite clinical results, the mechanisms of how OMT works remain unclear. The fascial system is described as a tensional network that envelops the human body. Direct or indirect manipulations of the fascial system are a distinctive part of OMT.
Objective: This review describes the biological effects of direct and indirect manipulation of the fascial system.
Material and methods: Literature search was performed in February 2016 in the electronic databases: Cochrane, Medline, Scopus, Ostmed, Pedro and authors’ publications relative to Fascia Research Congress Website.
Results: Manipulation of the fascial system seems to interfere with some cellular processes providing various pro-inflammatory and anti-inflammatory molecules. Discussion: Despite growing research in the osteopathic field, biological effects of direct or indirect manipulation of the fascial system are not conclusive.
Conclusion: To elevate manual medicine as a primary intervention in clinical settings, it’s necessary to clarify how OMT modalities work in order to underpin their clinical efficacies.
Link to Paper
Parravicini, G., Bergna, A., (2017). Biological effects of direct and indirect manipulation of the fascial system. Narrative review, Journal of Bodywork & Movement Therapies