The day of treatment each subject will completed the STAI-1 (form Y) questionnaire to evaluate the anxiety of the moment. Saliva collection will be made by passive drooling continuously for 5 minutes in a 15 ml falcon tube. Saliva will be collected before, immediately after and 30 minutes after application of a true CV4 technique or application of a sham technique performed by different osteopaths. Saliva samples will be immediately frozen at -20°C for subsequent analysis.