Orthosis and method for the placement of an orthosis

An orthosis for supporting an arm of a person, the orthosis comprising:

• a securing device for securing the orthosis to a torso of the person;
• and
• a positioning device for supporting and fixing a supported/fixed arm portion that is one of a forearm, elbow and/or upper arm, relative to a person's shoulder associated to that supported/fixed arm portion, the positioning device being supported by the securing device, the securing device comprising an abdominal strap device and a shoulder strap device, the abdominal strap device surrounding the torso in a transversal plane when the orthosis is placed on a person, and the shoulder strap device running over a person's shoulder opposite of the supported/fixed arm portion, wherein the shoulder strap device comprises straps comprising a shoulder strap and a chest strap connected to said shoulder strap, said straps being hinged to a distal end and to a proximal end of the positioning device and to a ventral portion of the abdominal strap device.