A system (10, 150, 200, 250, 350, 400, 500, 510, 870, 900) to support an arm (Ar) of a user (U), including: a harness configured to be worn on the body of an user； an arm support (505) coupled to the harness configured to support a user's arm, the arm support being configured to accommodate the movement of the arm while following the movement without substantially interfering with the movement of the user's arm； and one or more compensation elements coupled to the arm support to apply a compensation force to at least partially compensate a gravitational force acting on the arm when the user moves and the arm support follows the movement of the user's arm, where The arm support includes: a first arm support segment (56) pivotally coupled to the harness around a first vertical axis (Dav) such that the first arm support segment is rotatable substantially horizontally around the first axis vertical relative to the harness； and a second arm support segment (62) pivotally coupled to the first arm support segment such that the second arm support segment is rotatable about a second axis (Dah) generally orthogonal to the first vertical axis, and where the element or the various compensation elements include an elastic element (74, 415, 636) mounted on the second arm support segment, characterized in that: the element or the various compensation elements provide a force profile that varies the force of compensation based on an orientation of the arm support, and where the force profile applies a greater force on the arm when the arm is in a raised position, and less force when the arm is in a lowered position.Un sistema (10, 150, 200, 250, 350, 400, 500, 510, 870, 900) para soportar un brazo (Ar) de un usuario (U), incluyendo: un arnés configurado para ser llevado puesto en el cuerpo de un usuario； un soporte de brazo (505) acoplado al arnés configurado para soportar un brazo del usuario, estando configurado el soporte de brazo para acomodar el movimiento del brazo al mismo t
