Effectiveness of Self-posturotherapy on the Elimination of Residual Fragments After Treatment of Lower Calyx Urinary Stones by Extracorporeal Lithotripsy or Retrograde Flexible Ureteroscopy.

pré Inclusion Criteria: * Patient having read and signed the consent form for participation in the study • Patient candidate for an intervention on a lower calyx stone \<15mm by LEC or URSS Patients meeting all of the following criteria may be definitively included in the study: * Patient treated by LEC, or patient treated by URSS and for whom the presence of lower calyceal fragments has been observed by endoscopy * Absence of JJ stent (patients for whom a JJ stent was implanted after URSS or before LEC may be included as soon as it is removed) Exclusion Criteria: * Patients presenting one of the following criteria will not be included in the study: * Renal or ureteral malformation: ureteral stenosis, pyelo-ureteral junction syndrome, horseshoe kidney, para calyceal diverticulum, pelvic kidney. * LEC session interrupted due to treatment intolerance * Physical disability making posturotherapy impossible (particularly spinal, etc.), morbid obesity, major gastroesophageal reflux, heart or respiratory failure. * Balance disorder which would not allow self-posturotherapy to be carried out alone. * Patient under legal protection, under guardianship or under curatorship * Posturotherapy carried out while wearing a JJ probe * Posturotherapy carried out by a third party (physiotherapist or other) * Pregnant or breastfeeding patient * Patient not affiliated to the French social security system * Impossibility of providing the subject with informed information and/or giving written informed consent: dementia, psychosis, disorders of consciousness, non-French speaking patient * Treatment that may modify the clearance of fragments (beta blocker, diuretic, etc.) * Patient included in another therapeutic study protocol