This joint assist device is provided with an inner support plate (1b) disposed on the inner side of a joint, an outer support plate (1a) disposed on the outer side of a joint, an interconnecting member (30) for interconnecting the inner support plate (1b) and the outer support plate (1a) on the rear side of the knee, a first inner arm (10b) pivotably provided to the upper end side of the inner support plate (1b), a second inner arm (20b) pivotably provided to the lower end side of the inner support plate (1b), a first outer arm (10a) pivotably provided to the upper end side of the outer support plate (1a), and a second outer arm (20a) pivotably provided to the lower end side of the outer support plate (1a). The joint assist device is characterized in that the first inner arm (10b), the first outer arm (10a), the second inner arm (20b), and the second outer arm (20a) are constituted from a thermoplastic resin. The present invention enables adjustment that fits the body shape of the user, and makes it possible to reduce the conspicuousness of a prosthetic fitting.La présente invention concerne un dispositif dassistance articulaire comportant une plaque interne de support (1b) disposée sur la face interne dune articulation, une plaque externe de support (1a) disposée sur la face externe dune articulation, un élément dinterconnexion (30) assurant linterconnexion entre la plaque interne de support (1b) et la plaque externe de support (1a) à larrière du genou, un premier bras interne (10b) monté pivotant du côté de lextrémité supérieure de la plaque interne de support (1b), un second bras interne (20b), monté pivotant du côté de lextrémité inférieure de la plaque interne de support (1b), un premier bras externe (10a), monté pivotant du côté de lextrémité supérieure de la plaque externe de support (1a) et un second bras externe (20a) monté pivotant du côté de lextrémité inférieure de la plaque externe de support (1a). Ledit dispositif dassistance articulaire est caractéris
