Shoulder joint

The invention relates to a shoulder hinge, wherein, two slippers (3,4) are guided together to unfold a mechanical arm (2), then the slippers (3,4) are connected together while unfolding the mechanical arm (2) to ensure the mechanical arm (2) fixed on the slippers (3,4) capable of moving simultaneously with the slippers (3,4) connecting with each other. The mechanical arm (2) is preferred composedof an upper arm (11) and a lower arm (12), which movement is coupled by two rollers (13, 14) connecting with each other actually. Due to the actual connection, the unfolding action of the mechanical arm (2) can simultaneously actuate the spreading action of the mechanical arm (2). Thereby, all motions can be performed just by one drive device according to the structure of the invention.