Inclusion Criteria:  Mother 18 yrs and older who chose to breast-feed (exclusive or not) Singleton newborn after 37 weeks of gestation, weighing at least 2500 g at birth, after 36 hours of life Pain during lactation greater than 7 (scale 0 to 10) in one or both breasts Usual known aids ineffective to reduce pain during lactation Mother speaking and understanding French Mother affiliated or beneficiary to a health system Signed informed consent.  Exclusion Criteria:  Medical contraindication to osteopathic treatment (non stabilized infection, acute neurological pathology, tumor or cancer process, maternal psychiatric disorders) Severe congenitale malformation, especially not allowing normal lactation Patient under legal protection Persons deprived of their liberty by judicial or administrative decision