The choice of recruiting healthy volunteers was oriented by the current lack of clear and objective evidences on the impact of osteopathic techniques on the thoraco-abdominal diaphragm. Therefore, since we were not aware of the potential influence of the osteopathic treatment on diaphragmatic motion and function, we judged the identification of a diseased population suitable for treatment an arbitrary choice and excluded subjects with known, proved, or likely diaphragmatic dysfunction.