SummaryImmobility in plaster, continuous stretching by a Kirschmer thread, anesthetic infiltration of the ligaments are three surgical methods which all aim at the same end and which all obtain the same result : suppression of the muscular contraction which is always present in inflammatory lesions of the joints.Facts show that if muscular contraction is abolished, involution of the inflammatory process and local reparation is favoured. Osteogenesis is started.These physiopathological modifications can only be the consequence of the restoration of a normal circulation. Excluding germ virulence, the physiopathology of inflammatory lesions of articulations may be so described.The microbic focus in the articulation determines a local irritation which induces a reflex contraction of the muscles. This in its turn, brings forth local vasomotor disturbances (capillary stasis ?) which increase the local irritation and favour the formation of a septic focus by considerably reducing local defenses brought by the blood stream. Bearing in mind this reflex mecanism of vasomotor reactions, one can understand the inflammatory susceptibility of the joints, the rapid extension of microbic foci and their early influence on the patient’s health.